Lithium-sulphur batteries are gaining importance due to high energy density (theoretical energy 2567 Wh·kg^-1), which is almost one order of magnitude higher than that of the Li-ion batteries and also thank to their superior cost efficiency, based on the availability, non-toxicity, and cost of sulphur. However, the Li-S cells mechanism is complex at molecular level and includes the dissolution of high soluble lithium polysulphide intermediates (Li₂S_x, where 4≤x≤8) in the electrolyte leading to losses of active material and the shuttle effect. A suitable strategy in the design of electrodes is based on the incorporation of functional inorganic materials over the graphene-host support, used in the cathode, to scavenge polysulphides.

The synthesis of hybrids rGO-Mo by hydrothermal route and rGO-Mo₂C by colloidal method is here reported as well as its beneficial role in the adsorption of polysulphides and alleviation of the shuttle effect in Li-S cells. The absorption of this catalytic sulphur host materials has been tested through a white light test and quantified using the UV-vis spectroscopy.

Complementary XPS measurements have been carried out to demonstrate the chemical binding of polysulphides mediated by molybdenum species. Overall, the rGO-Mo nanocomposite shows molybdenum oxide particles on the surface: these moieties increase the hydrophilic character of the host matrix and promotes the capture of lithium polysulfides from the electrolyte. This mechanism limits the shuttle effect and improves an effective utilization of sulphur in the Li-S cell.