Lewis Acid–Base Dual Sites for Stabilizing Li–S Batteries: A Guideline for Doping in p-Block Atoms

Carbon-based hosts in lithium-sulfur batteries often need a polarity enhancement design to strengthen the suppression of polysulfide (PS) shuttles. Among various polarity enhancement strategies, heteroatom doping design is the most extensive and basic; however, at present, researchers are unaware of regulation through the Lewis acid-base pair. In this work, nitrogen and boron atoms were selected as Lewis acid-base double sites to adsorb lithium and sulfur in PS through a detailed theoretical preliminary screening of atoms in the p-block. Finite element analysis showed that the kinetics of nitrogen and boron sites helped lithium ions to diffuse rapidly and provided an anode perspective, which is widely ignored at present through ToF-SIMS. The NB@C host effectively inhibited the escape of active sulfur and mitigated the corrosion of the lithium metal anode. This work explains the functional mode of heteroatom doping in the p-block and the unsatisfactory effect of halogen doping, which can be used as a reference guideline for doping in the p-block. The selected nitrogen and boron doping is expected to become a basic doping combination for designing a more multifunctional cathode.