Supramolecular Polymerization Promoted in Situ Fabrication of Nitrogen-Doped Porous Graphene Sheets as Anode Materials for Li-Ion Batteries

A novel strategy of utilizing supramolecular polymerization for fabricating nitrogen doped porous graphene (NPG) with high doping level of 12 atom% as the anode material for lithium ion batteries is reported for the first time. The introduction of supramolecular polymer (melamine cyanurate) functions not only as a spacer to prevent the restacking of graphene sheets but also as a sacrificial template to generate porous structures, as well as a nitrogen source to induce in situ N doping. Therefore, pores and loose-packed graphene thin layers with high N doping level are very effectively formed in NPG after the annealing process. Such highly desired structures immediately offer remarkably improved Li storage performance including high reversible capacity (900 mAh g^-1 after 150 cycles) with good cycling and rate performances. The effects of annealing temperature and heating rates on the final electrochemical performance of NPG are also investigated. Furthermore, the low cost, facile, and scalable features of this novel strategy may be helpful for the rational design of functionalized graphene-based materials for diverse applications.