Graphene Quantum Dots (GQDs) Surface Functionalization to Enhance the Cycle Stability and Electron Path on Lithium Sulphur Batteries

Abstract

Recently, sulphur has been considered as a promising material lithium rechargeable battery cathode due to a superior specific capacity of 1672 mAh/g to other traditional metal oxides/phosphates cathodes, abundant resources, low cost, and environmental friendliness. Despite these advantages, it has been faced with rapid capacity fading due to dissolution of polysulphides and precipitation of lithium sulphides. Furthermore, low electrical conductivity of sulphur leads to low utilization of the active materials as a sulphur electrode. To make up for the weak points of lithium sulphur batteries, many researchers have studied various methods to overcome these problems by controlling matrix and additive of liquid electrolyte. In this study, graphene quantum dots (GQDs) were used to surface functionalizer that were able to support electron path and alleviate polysulphides dissolution, which have a role in conducting agents and various functional additives, results in high specific capacity and good cycle ability in lithium sulphur batteries.