Synthesis of graphene@Fe3O4@C core–shell nanosheets for high-performance lithium ion batteries

Abstract

Development of anode materials with high capacity and long cycle life, while maintaining low production cost is crucial for achieving high-performance lithium-ion batteries (LIBs). Herein, we report a simple and cost-effective one-pot solvothermal method to synthesize graphene@Fe₃O₄@C core–shell nanosheets as a LIB anode with improved electrochemical performances. In this case, ferrocene was used as the precursor for both Fe₃O₄ and carbon, while graphene oxide was used as a template for the resultant two-dimensional nanostructure and conductive graphene backbone. The obtained graphene@Fe₃O₄@C core–shell nanosheets have a unique core–shell nanostructure, ultrasmall Fe₃O₄ nanoparticles (∼6 nm), and a high surface area of ∼136 m² g⁻¹, as well as show a high reversible capacity of ∼1468 mA h g⁻¹, an excellent rate capability and long cycle life, which reflects the ability of graphene backbone to enhance the conductivity and carbon coating to prevent agglomeration of iron oxide nanoparticles. These findings provide a new approach to the design and synthesis of high-performance anode materials.