Facile Synthesis of FeS2 Quantum‐Dots/Functionalized Graphene‐Sheet Composites as Advanced Anode Material for Sodium‐ion Batteries

Abstract FeS 2 quantum‐dots/functionalized graphene‐sheet ( QDs / FGS ) composites are prepared by a facile and scalable method. The FeS 2 QDs / FGS composites can be used as anode materials for sodium‐ion batteries. The FeS 2 QDs / FGS composites can achieve large specific discharge and charge capacities of 742 and 683 mAh •g −1 (based on the total mass of the FeS 2 QDs / FGS composites) at the current density of 0.5 A•g −1 in the first cycle, respectively, and retain a reversible charge capacity of 552 mAh •g −1 after 100 cycles. The FeS 2 QDs / FGS composites can display high specific capacities of 452 and 315 mAh •g −1 at the high current densities of 2 and 5 A•g −1 . These results indicate that the FeS 2 QDs / FGS composites have good cycle performance and high rate capability, making them promising candidates as anode material for sodium‐ion batteries.