Flower-like Vanadium Suflide/Reduced Graphene Oxide Composite: An Energy Storage Material for Aluminum-Ion Batteries

A flower-like vanadium sulfide/reduced graphene oxide (VS₄ /rGO) composite was prepared by a typical hydrothermal method and it was investigated as cathode for aluminum-ion batteries with non-inflammable and non-explosive ionic-liquid electrolytes. The charge/discharge performance measurements were performed in a voltage range of 0.1-2.0 V versus Al/AlCl₄^- , which gave an initial charge/discharge specific capacity af approximately 491.57 and 406.94 mA h g^-1 , respectively, at a current density of 100 mA g^-1 . Additionally, in the cycling performance, the discharge capacity was observed to remain over 80, 70, and 60 mA h g^-1 at current densities of 100, 200, and 300 mA g^-1 after 100 cycles, respectively. The result of a coulombic efficiency over 90 % after 100 cycles and high retained capacity indicate that the composite is a favorable cathode material for new rechargeable aluminum-ion batteries.