(774g) Few Layers MoSe2 Incorporated with Nitrogen Doped Graphene Sheet for High Performance Lithium Sulfur Batteries

Rechargeable lithium sulfur (Li-S) batteries, which utilize sulfur as cathode materials, have been examined as one of the most promising energy storage device, owing to their high energy density of 2600 Wh/kg and theoretical capacity of 1672 mAh/g. Apart from that, the cathode has the advantages of sulfur abundance, low cost and environmental friendliness. However, the capacity fading in the battery performance attributed to the dissolution of long-chain lithium polysulfides (Li₂S_x, x = 4 - 8) causing damaging “shuttle effect” becomes the main obstacle in Li-S batteries system. Introducing anchoring materials, transition mental dichalcogenides (TMDCs) to the cathode design has been confirmed as an efficient way to trap polysulfide species. Here, we present a novel material, a two-dimensional composite, molybdenum diselenide on nitrogen doped reduced graphene oxide sheet (MoSe₂/N-rGO), which is synthesized by CVD method to provide a strong chemisorption between the polysufides and MoSe₂. We found remarkable improvement in the capacity retention comparing to N-rGO electrode (without MoSe₂). It is observed that smaller percentage use of MoSe₂ could give a better battery performance due to its unpleasant electrical insulating properties. An optimal amount of MoSe₂ in the composite is discovered to be around 10% which provides a reference for future studies.