S@GO as a High-Performance Cathode Material for Rechargeable Aluminum-Ion Batteries

Aluminum-ion batteries (AIBs) are considered promising post lithium-ion batteries owing to their outstanding safety, gravimetric and volumetric capacities, and cost efficiency advantages. However, one practical obstacle to their development is the lack of reliable cathode materials that can be coupled with the distinguished Al anode. To address this issue, we synthesized a S@GO composite material for use as a cathode material in AIBs. The synthesized S@GO material exhibits a rod structure with a diameter of around 100 nm. Inside these nanorods, sulfur nanoparticles with a size of around 5 nm were uniformly anchored on the graphene sheets. By taking the advantage of an introduction of graphene sheets, the capacities were significantly preserved, displaying a capacity that was more than double that of a bare S active material. In addition, a 3000-cycle long-term repeated charge/discharge measurement exhibited extremely stable capacity values with a high Coulombic efficiency of 98% at the 3000th cycle. The charge/discharge processes were clearly shown during the repeated cycling measurement at a high current density of 1000 mA g−1. This work is expected to stimulate further study of elemental S used as a cathode material for high-performance AIBs.