Reduced graphene oxide@CoSe₂ interlayer as anchor of polysulfides for high properties of lithium-sulfur battery

Lithium sulfur (Li-S) battery is regarded as one of the most appealing competitors for the succeeding generation energy storage systems. Nevertheless, the pragmatical application of Li-S battery on a large-scale is obstructed by its short cycle life and low Coulombic efficiencies, originating from the notorious shuttle effect. To resolve this issue, in this manuscript, the reduced graphene oxide@CoSe₂ (rGO@CoSe₂) is proposed for the first time to revise the part of separators in the Li-S battery to restrain the shuttling of polysulfides with the aid of graphene with physical absorption and CoSe₂ particles with strong chemical anchoring of lithium polysulfides. The results indicate that the Li-S battery fabricated with rGO@CoSe₂-redevised separator presents high initial discharge capacities of 1180 mAh g^-1 at 0.2 C (1C = 1675 mAh g^-1) and long cycle stability at 0.5 C with a low capacity decrease rate of 0.0856% per cycle. The proposed approach demonstrates a viable way for practical application of Li-S battery with good electrochemical properties.