Innovative N-doped graphene-coated WS2 nanosheets on graphene hollow spheres anode with double-sided protective structure for Li-Ion storage.

Abstract By skillfully designing the double-sided protective structure, WS 2 nanosheets in situ grow on reduced graphene oxide hollow spheres (Hs-rGO). Then nitrogen doped graphene (NG) is coated on the outer layer to obtained NG@WS 2 @Hs-rGO. Double-sided protective structure of NG@WS 2 @Hs-rGO is successfully fabricated via a facile synthesis strategy. When evaluated as an anode material for Lithium-ion batteries (LIBs), NG@WS 2 @Hs-rGO exhibits a high specific capacity of 1309.4 mAh g−1 at 100 mA g−1 and excellent rate capability (166.1 mAh g−1 at a high current density of 4000 mA g−1). More strikingly, at a high current density of 1000 mA g−1, the NG@WS 2 @Hs-rGO electrode delivers a discharge capacity of 300.9 mAh g−1 after 320 cycles. The capacity retention of the electrode material reaches as high as 106% of the discharge capacity after the 10th cycle. Internally, the elastic Hs-rGO provides space for the bulk expansion of WS 2. Externally, the outer layer of WS 2 coated with NG not only improves the conductivity, but also provides more active sites for Li ion storage. The double-sided protective structure makes NG@WS 2 @Hs-rGO a potential anode material for light and high-performance LIBs. Graphical abstract Image 1 Highlights • WS 2 nanosheets in situ grow on reduced graphene oxide hollow spheres. • N-doped graphene is coated to obtained double-sided protective structure. • The battery with 3D hollow spherical structure fully uses of graphene. • A high discharge capacity of 300.9 mAh g−1 is obtained after 320 cycles at 1000 mA g−1. • Full-cells with coin type were firstly assembled with LFP/C as cathode and NG@WS 2 @Hs-rGO as anode. [ABSTRACT FROM AUTHOR]