Ultra‐Dispersed α‐MoC1−x Embedded in a Plum‐Like N‐Doped Carbon Framework as a Synergistic Adsorption–Electrocatalysis Interlayer for High‐Performance Li–S Batteries

Abstract

AbstractThe shuttle effect and sluggish redox kinetics of lithium polysulfides (LiPSs) severely hinder the scalable application of lithium‐sulfurr (Li–S) batteries. Herein, the highly dispersed α‐phase molybdenum carbide nano‐crystallites embedded in a porous nitrogen‐doped carbon framework (α‐MoC1−x@NCF) are developed via a simple metal–organic frameworks (MOFs) assisted strategy and proposed as the multifunctional separator interlayer for Li–S batteries. The inlaid MoC1−x nanocrystals and in situ doped nitrogen atoms provide a strong chemisorption and outstanding electrocatalytic conversion toward LiPSs, whereas the unique plum‐like carbon framework with hierarchical porosity enables fast electron/Li+ transfer and can physically suppress LiPSs shuttling. Benefiting from the synergistic trapping‐catalyzing effect of the MoC1−x@NCF interlayer toward LiPSs, the assembled Li–S battery achieves high discharge capacities (1588.1 mAh g−1 at 0.1 C), impressive rate capability (655.8 mAh g−1 at 4.0 C) and ultra‐stable lifespan (a low capacity decay of 0.059% per cycle over 650 cycles at 1.0 C). Even at an elevated sulfur loading (6.0 mg cm−2) and lean electrolyte (E/S is ≈5.8 µL mg−1), the battery can still achieve a superb areal capacity of 5.2 mAh cm−2. This work affords an effective design strategy for the construction of muti‐functional interlayer in advanced Li–S batteries.