Nitrogen-doped graphene–Fe3O4 architecture as anode material for improved Li-ion storage

Abstract

A well-organized flexible composite of nitrogen-doped graphene–Fe₃O₄ (N-G–Fe₃O₄) is successfully synthesized through a green and facile chemical method. The half cells based on the synthesized N-G–Fe₃O₄ composite exhibit a reversible specific capacity approaching about 800 mA h g⁻¹, after 100 cycles at a current density of 100 mA g⁻¹. For the composite, the graphene plays a flexible confinement function to encapsulate Fe₃O₄ particles, accommodating the volume change and preventing the agglomeration of Fe₃O₄ nanoparticles. Furthermore, the nitrogen doping can greatly improve the electrical conductivity of graphene, and decrease the energy barrier for Li ion penetration and effectively modify the surface chemistry at the anode/electrolyte interface to form a stable solid electrolyte interface (SEI) layer. As a result, this unique N-G–Fe₃O₄ composite can dramatically improve the cycling performance and rate capacity as an anode material for lithium ion batteries.