Mass production of porous Fe3O4 nanoparticle networks wrapped with ultrathin nitrogen-doped carbon for superior lithium ion batteries

Abstract By virtue of the natural abundance, environmental benignity, and high theoretical capacity, there is an increasing research attention on magnetite micro-/nano-structures serving as alternative anode materials for lithium-ion batteries (LIBs). The facile and efficient synthetic methods are still of urgency and challenging for their mass production. Herein, a low-temperature oxidation accompanied by a dicyandiamide-vapor nitridation strategy is proposed to synthesize ultrathin nitrogen-doped carbon layer wrapping porous magnetite nanoparticle (Fe3O4@NC) networks. As the synthesis approach only contains two-step annealing process and only commercial FeC2O4⋅2H2O and dicyandiamide are utilized, the as-developed approach is facile, low cost, and could effectively reduce the pollution and enhance the atom economy. When served as anode materials for LIBs, the porous Fe3O4@NC electrodes exhibit superior charge/discharge performances at high current density (847.5 mAh g−1 at 10.0 A g−1) and remarkable long-term cycling stability (a high specific capacity of 1125.7 mAh g−1 remains even after 600 cycles at 1.0 A g−1), outperforming most of Fe3O4/carbon-based structures. The as-proposed mass production synthetic method can be expected to pave a new avenue to design high-performance anode materials for various battery applications.