Graphene-Supported Mesoporous Silica Nanosheets as Sulfur Hosts for Highly Stable Lithium-Sulfur Batteries

Abstract

Herein, we develop a novel approach to fabricate graphene-supported mesoporous silica nanosheets (G-mesosilica nanosheets) as sulfur cathode hosts for Li-S batteries. The resultant G-mesosilica nanosheets are monodispersed and possess a hierarchical mesoporous structure. The large mesopores (14 nm) ensure to encapsulate high amounts of sulfur. Moreover, the small mesoporous (2.8 nm) can effectively prevent large polysulfide molecules escaping from cathode. As a consequence, the sulfur cathodes with unique G-mesosilica nanosheets as the sulfur hosts can significantly improve the long-term cycle performance (81% capacity retention after 500 cycles) of Li-S batteries.

Keywords: hierarchical mesoporous structure, Li-S batteries, lithium polysulfides, sulfur hosting materials, monodispersed nanosheets