How to make inert boron nitride nanosheets active for the immobilization of polysulfides for lithium–sulfur batteries: a computational study

Abstract

The search for effective anchoring nanomaterials for the immobilization of soluble lithium polysulfide (Li₂S_n) species to suppress their shuttling effect has been a key scientific issue for the large-scale practical application of lithium-sulfur (Li-S) batteries. In this work, by means of comprehensive density functional theory (DFT) computations, we systematically investigated the potential of a series of doped and defective boron nitride (BN) nanosheets as chemical immobilizers for the soluble Li₂S_n species. Our results revealed that the introduction of dopants and defects can enhance the binding strength of Li₂S_n species with BN nanosheets due to the strong LiN or SB interaction. In particular, the doped BN nanosheets that can moderately interact with Li₂S_n species are shown to exhibit outstanding anchoring effects for Li-S batteries because they can keep a balance between the binding strength and integrity of Li₂S_n species. Therefore, by carefully controlling the type of dopants, the inert BN nanosheet can be converted to quite a promising electrode material with high efficiency for Li-S batteries.