Fe7S8 Nanoparticles Anchored on Nitrogen-Doped Graphene Nanosheets as Anode Materials for High-Performance Sodium-Ion Batteries.

Despite high sodium storage capacity and better reversibility, metal sulfides suffer from relatively low conductivity and severe volume change as anode materials of sodium-ion batteries (SIBs). Introducing a conductive carbon matrix is an efficient method to enhance their sodium storage performance. Herein, we present iron sulfide (Fe7S8) nanoparticles anchored on nitrogen-doped graphene nanosheets fabricated through a combined strategy of solvothermal and postheating process. The as-prepared composite exhibits appealing cycling stability (a high discharge capacity of 393.1 mA h g-1 over 500 cycles at a current density of 400 mA g-1 and outstanding high-rate performance of 543 mA h g-1 even at 10 A g-1). Considering the excellent sodium storage performance, this composite is quite hopeful to become a potential candidate as anode materials for future SIBs.