Fabrication of nitrogen-doped porous graphene hybrid nanosheets from metal-organic frameworks for lithium-ion batteries

To achieve a good electrochemical performance of lithium-ion batteries (LIBs), the design and optimization of the anode is a key issue. Herein, the fabrication of nitrogen-doped porous graphene hybrid nanosheets (denoted as N-PGNS) is proposed via a simple functional group-induced growth of zeolitic imidazolate framework (ZIF-8) on graphene oxides (GO) followed by a one-step pyrolysis strategy. Detailed characterizations reveal that the N-doped porous carbon derived from ZIF-8 is homogeneously anchored on graphene, and can provide high electroactivity and numerous diffusion channels for fast Li+ transport. Meanwhile, the incorporation of graphene as a conductive framework and supporting substrate can accelerate the transfer of electrons. Taking advantage of the synergistic role between the graphene framework and N-doped porous carbon, the N-PGNS exhibits a stable reversible specific capacity of 741.8 mA h g(-1) as the anode for LIBs, which is notably higher than that of the N-doped porous carbon obtained directly by pyrolysis of ZIF-8. Furthermore, the N-PGNS electrodes also show superior electrochemical stability with an initial capacity of 90.38% over 1000 cycles at 5 A g(-1). The current strategy, which can control and adjust the growth of ZIF-8 via the inducing effect of GO, provides a promising solution to construct graphene hybrid nanosheets for high-performance LIBs.