Facile Microwave-Impulse Synthesis of Multifunctional rGO/MoS₂/MoO₂ Composites as a Permselective Separator-Coating Layer for Li–S Batteries

The commercial applications of Li–S batteries (LSBs) can be expanded by the development of shuttle effect-prohibiting multifunctional materials using high-efficiency and energy-saving methods. Here, we report a facile microwave-impulse-based method to synthesize multifunctional rGO/MoS2/MoO2 heterostructure characterized with lamellar MoS2/MoO2 heterojunctions attached to reduced graphene oxide (rGO) sheets. Microwaves can directly work on the precursor materials, and the preparation process can be completed in only 100 s. The rGO/MoS2/MoO2 composite could give strong chemisorption ability and excellent catalytic activity of lithium polysulfides (LPSs) while maintaining a relatively high conductivity from the rGO matrix. Moreover, permselective rGO/MoS2/MoO2 layers with numerous micron-size pores can trap polysulfide anions while promoting the diffusion of Li+, which is of great significance in efforts to improve the cycling stability and reaction kinetics of LSBs. A cell with an rGO/MoS2/MoO2-coated separator retains 62.1% of its capacity with a 0.12% capacity decay per cycle over 300 cycles at 0.5C. This work offers an innovative route for the rapid preparation of multifunctional separators for LSBs.