Template free construction of a hollow Fe3O4 architecture embedded in an N-doped graphene matrix for lithium storage.

Abstract

The rational design and fabrication of electrode materials is a significant, yet highly challenging task. In this work, mesoporous Fe3O4 nanostructures featuring 3D structured hollow nanoparticles decorated by N-doped graphene with an average size of 10 nm were synthesized by a combination of hydrothermal and post carbonization techniques, and were subsequently studied as an anode material for lithium ion batteries. This hollow nanoarchitecture anchored on N-doped graphene sheets, possessing a large specific surface area and enhanced volumetric capacity, offers maximum lithium storage, facilitates rapid electrochemical kinetics, buffers volume changes during the lithium ion insertion and extraction processes, and removes detrimental active sites due to N incorporation, which is important for improving the recycling ability of anode materials. High reversible capacities, excellent rate-capability and stable performance were continuously observed. Accordingly, graphene-based composites that intercalate hollow Fe3O4 nanocrystals into N-doped graphene sheets have been demonstrated to be promising electrode materials for energy storage.