Recent advances on graphene-based materials as cathode materials in lithium-sulfur batteries

Representing one of the advanced energy storage devices, lithium-sulfur batteries have a wide range of possible applications. While it serves as a promising energy storage system, it should adhere to multiple important criteria before a large-scale application can be realized. The novel uses of graphene can resolve the deficiencies of lithium-sulfur batteries. Graphene is an exceptional conductive material with excellent mechanical stability and is extremely flexible. Because of its large porosity value, it enables a high sulfur loading within its matrix and effectively encapsulates polysulfide. Graphene oxide, on the other hand, often exhibits a number of functional groups capable of chemically bonding to polysulfides, resulting in good capability for polysulfide entrapping. Physical containment of sulfur by graphene materials and its chemical interactions with sulfur can be further improved by designing 3D graphene-sulfur configurations through doping of functional groups or heteroatoms. This review article offers an insight into the strategies for achieving a high sulfur loading cathode with a long cycle life and high retention potential through sulfur containment and carbon host functionalization, for which this review focuses on the functionalization of graphene. Throughout these strategies, significant performance improvements can be achieved.