Trade-off effect of 3d transition metal doped boron nitride on anchoring polysulfides towards application in lithium-sulfur battery.

The trade-off effect between Li bond and S bond for anchoring polysulfides on 3d-transition metal doped BN towards the application in Lithium-sulfur battery. [Display omitted] • A trade-off effect is detected between TM-S and Li-N bonds for anchoring LiPSs/S 8. • A closer d -band center of TM-BN benefits the TM-S bond and weakens the Li-N bond. • A closer d -band center of TM-BN leads to a lower decomposition energy of Li 2 S. • DME/DOL electrolyte has a little effect on the adsorption of LiPSs/S 8 on TM-BN. • Ti/V/Cr-BN stands out from TM-BNs for use in LSB. Sulfur cathodes in lithium-sulfur batteries (LSBs) suffer from the notorious "shuttle effect", low sulfur use ratio, and tardy transformation of lithium polysulfides (LiPSs), while using two-dimensional (2D) polar anchoring materials combined with single-atom catalysis is one of the promising methods to address these issues. Herein, the 3 d transition metal (TM) doped 2D boron nitrides (BN), labeled as TM-BN, are studied for the anchoring and redox kinetics of LiPSs using first principles calculations. From the simulated results, the TM atom and adjacent N atoms are active adsorption sites for binding S atoms in LiPSs/S 8 and Li atoms in LiPSs, respectively. A negative d -band center closer to the Fermi level of TM-BN is key for enhancing the binding strength of TM-S and lowering the Li 2 S decomposition energy barrier, while it deteriorates the activity of adjacent N atoms. Fortunately, the electrolyte environment has little effect on the superiority of the TM-BN for binding polysulfides/S 8 , guaranteeing the sturdy anchor of polysulfides/S 8 in realistic conditions. The trade-off effect on the activities of TM and adjacent N atom sites in TM-BN for binding LiPSs highlights the excellence of Ti/V/Cr-BN as modification materials for LSB. [ABSTRACT FROM AUTHOR]