Hierarchical porous Fe3O4@N-doped carbon nanoellipsoids with excellent electrochemical performance as anode for lithium-ion batteries

Fe3O4 has broad development aspect as an anode material for rechargeable lithium ion batteries due to its high specific capacity and low cost. The intrinsic low electrical conductivity and huge volume variation during cycle processes still hinder its practicability. Herein, we have explored a novel hierarchical porous Fe3O4@N-doped carbon (HP-Fe3O4@NC) nanoellipsoids by adopting mesoporous Fe2O3 nanoparticles as the core substance and dopamine-derived N-doped carbon as a protective layer to improve the electrochemical performance of the Fe3O4 composite. The composite exhibits impressive electrochemical performance with a high reversible capacity of 904 mA h g(-1) at 500 mA g(-1), a high rate capability of 458 mA h g(-1) at 5 A g(-1), and a long cycle life of 1500 cycles at 2 A g-1. Moreover, the composite exhibits much higher rate capability and better cycle stability than the solid Fe3O4@N-doped carbon (S-Fe3O4@NC) nanocubes and the pure Fe3O4 nanoellipsoids. The improved electrochemical performance of the HP-Fe3O4@NC nanoellipsoids benefits from the hierarchical porous structure and N-doped carbon coating. This strategy offers a new pathway for preparing advanced electrode materials for lithium ion batteries.