A new metallic π-conjugated carbon sheet used for the cathode of Li-S batteries.

Lithium-sulfur (Li-S) batteries are considered as the most promising next generation high density energy storage devices. However, the commercialization of Li-S batteries is hindered by the shuttle effect of polysulfides, the low electronic conductivity of the sulfur cathode and a large volume expansion during lithiation. Herein, we predict a new two dimensional sp hybridized carbon allotrope (PHE-graphene) and prove its thermodynamic and kinetic stability.