Sulfur immobilization and lithium storage on defective graphene: A first-principles study

Motivated by the recent progresses and remaining technical challenges in Li-S battery, we employ defective graphene as a prototype cathode framework to illustrate how battery performance is influenced by the mesoporous carbon materials. We show that the immobilization of S unavoidably sacrifices its ability to further interact with Li, which leads to an enhanced cycle life but a decreased capacity. Based on our calculated results, we suggest a suitable S binding-energy range of ∼4-5 eV to balance the battery stability and capability under thermodynamic equilibrium conditions. Our results may promote the understanding and architecture design of Li-S battery.