Exfoliated V 5 S 8 /graphite nanosheet with excellent electrochemical performance for enhanced lithium storage

Abstract Nanostructured V5S8/graphite hybrid (V5S8/C) has been synthesized by a facile method combined solid state sulfuration with liquid exfoliation. The SEM and TEM results reveal that the V5S8/C hybrid is consisted of ultrathin V5S8 nanosheet and graphite flake. Due to efficient exfoliation of V5S8 sheet and effective incorporation of graphite flake, excellent electrochemical property of V5S8/C hybrid is demonstrated for lithium ion batteries. Surprisingly, V5S8/C hybrid delivers a high specific capacity of 1112 mAh g−1 at 0.1 A g−1; even up to 1.0 A g−1, a high capacity of 846 mAh g−1 is achieved after 700 cycles. Moreover, in situ XRD analysis indicates that the high capacity of V5S8/C is derived from the combined Li+ intercalation and conversion reactions. While the excellent cycle performance and superior rate capability are attributed to the reduced stacking of the V5S8 layers and overcoating of conductive graphite material, which can relax the strain and lower the barrier for Li+ insertion and extraction.