Theoretical Investigation of the Electrochemical Performance of Transition Metal Nitrides for Lithium-Sulfur Batteries

摘要

The notorious shuttle effect caused by the soluble polysulfide intermediates and the sluggish conversion kinetics in sulfur cathodes greatly hinder the practical application of lithium-sulfur (Li-S) batteries. Here we systematically investigate the electrochemical performance of a series of transition metal nitrides (TMNs) for Li-S batteries. All TMNs we investigated were found to have much stronger binding strength with polysulfide intermediates than graphene and transition metal sulfides (TMSs), indicating good performance of sulfur immobilization. These TMNs can also facilitate the lithium diffusion and activate the decomposition of Li2S, suggesting the good rate performance, high reversible capacity, and long cycling life of Li-S batteries. We also demonstrated that, among the TMNs, VN exhibits great potential as the anchoring materials in Li-S batteries with enhanced electrochemical performance. Our results provide a rational strategy to design and screen the materials to achieve high performance of Li-S batteries.