SnS_2 Nanoplatelet@Graphene Nanocomposites as High-Capacity Anode Materials for Sodium-Ion Batteries

摘要

Na-ion batteries have been attracting intensive investigations as a possible alternative to Li-ion batteries. Herein, we report the synthesis of SnS_2 nanoplatelet@graphene nanocomposites by using a morphology-controlled hydrothermal method. The as-prepared SnS_2/graphene nanocomposites present a unique two-dimensional platelet-on-sheet nanoarchitecture, which has been identified by scanning and transmission electron microscopy. When applied as the anode material for Na-ion batteries, the SnS_2/graphene nanosheets achieved a high reversible specific sodium-ion storage capacity of 725 mA hg~(-1), stable cyclability, and an enhanced high-rate capability. The improved electrochemical performance for reversible sodium-ion storage could be ascribed to the synergistic effects of the SnS_2 nanoplatelet/graphene nanosheets as an integrated hybrid nanoarchitecture, in which the graphene nanosheets provide electronic conductivity and cushion for the active SnS_2 nanoplatelets during Na-ion insertion and extraction processes.