Graphene-Based Mesoporous SnO₂ Nanosheets as Multifunctional Hosts for High-Performance Lithium–Sulfur Batteries

Lithium–sulfur batteries are among the most promising candidates for energy storage because of their overwhelming advantage in energy density and cost savings, but some issues such as the low electrical conductivity of sulfur and the polysulfide shuttle between the anode and cathode still need to be overcome. Herein, a graphene-based mesoporous SnO2 is designed and used as a multifunctional host to accommodate sulfur. SnO2 nanofilms with perpendicular mesochannels on graphene are able to not only immobilize lithium polysulfides through chemical adsorption and the pore constraints but also promote polysulfide redox reactions, which effectively suppress the shuttle effect during the charge and discharge process. Meanwhile, the conductive graphene substrate offers a good conductive network and stabilizes the mesostructure of SnO2 nanofilms during cycling. As a result, the designed hybrid with a high sulfur loading (69 wt %) exhibits exceptional electrochemical performance including a reversible capacity of 1380 mA h g–1 at 0.1 C over 200 cycles, and 680 mA h g–1 at 2 C over 500 cycles. Integration of mesoporous metal oxides with two-dimensional conductive substrates as multifunctional hosts provides a new approach for the design of high-performance cathode materials for lithium–sulfur batteries.