Nature-Inspired, Graphene-Wrapped 3D MoS 2 Ultrathin Microflower Architecture as a High-Performance Anode Material for Sodium-Ion Batteries.

In response to the increasing concern for energy management, molybdenum disulfide (MoS ₂ ) has been extensively researched as an attractive anode material for sodium-ion batteries (SIBs). The proficient cycling durability and good rate performance of SIBs are the two key parameters that determine their potential for practical use. In this study, nature-inspired three-dimensional (3D) MoS ₂ ultrathin marigold flower-like microstructures were prepared by a controlled hydrothermal method. These microscale flowers are constructed by arbitrarily arranged but closely interconnected two-dimensional ultrathin MoS ₂ nanosheets. The as-prepared MoS ₂ microflowers (MFs) have then been chemically wrapped by layered graphene sheets to form the bonded 3D hybrid MoS ₂ -G networks. TEM, SEM, XRD, XPS, and Raman characterizations were used to study the morphology, crystallization, chemical compositions, and wrapping contact between MoS ₂ and graphene. The ultrathin nature of MoS ₂ in 3D MFs and graphene wrapping provide strong electrical conductive channels and conductive networks in an electrode. Benefitting from the 2 nm ultrathin crystalline MoS ₂ sheets, chemically bonded graphene, defect-induced sodium storage active sites, and 3D interstitial spaces, the prepared electrode exhibited an outstanding specific capacity (606 mA h g ^-1 at 200 mA g ^-1 ), remarkable rate performance (345 mA h g ^-1 at 1600 mA g ^-1 ), and long cycle life (over 100 cycles with tremendous Coulombic efficiencies beyond 100%). The proposed synthesis strategy and 3D design developed in the present study reveal a unique way to fabricate promising anode materials for SIBs.