Enhanced cycle stability of iron(II, III) oxide nanoparticles encapsulated with nitrogen-doped carbon and graphene frameworks for lithium battery anodes

Abstract

Nitrogen-doped carbon-coated and graphene oxide-wrapped Fe3O4 nanoparticles were prepared using the electrostatic force between polyethyleneimine-functionalized Fe3O4 nanoparticles and graphene oxide layers, followed by annealing in an N2 atmosphere (Fe3O4@NCG). The electrochemical performance of Fe3O4@NCG was superior to that of graphene oxide- or reduced graphene oxide-wrapped Fe3O4 nanoparticles and carbon-coated Fe3O4 nanoparticles. Fe3O4@NCG exhibited stable specific capacity of ∼895 mAh g−1 after 350 cycles over the voltage range 0.001–3.0 V vs. Li/Li+. The superior performance of Fe3O4@NCG was attributed to the presence of a nitrogen-doped carbon layer and networks of reduced graphene oxide. The chemical route-derived Fe3O4@NCG may be a promising anode material for high-performance lithium-ion batteries.