On the role of oxidized graphene interfaces in lithium sulfur batteries: Thermodynamic and kinetic aspects using density functional theory

Abstract

The interaction of polysulfides with oxidized graphene layers containing functional groups (hydroxyl, epoxy and carboxyl groups) is analyzed using first-principles calculations, with the aim of using these structures to prevent polysulfide migration in lithium-sulfur batteries. An estimation of the residence time of the polysulfide on the oxidized surface is made based on transition state theory, with the finding that the studied oxidized graphene surfaces are not good enough candidates to prevent polysulfide migration in lithium-sulfur batteries. Even a value of 1.45 eV of the binding energy of the polysulfide to the surface is not enough to retain polysulfide for an important residence time.