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

作者：Li, Hongxi; Zheng, Wen; Wu, Hongzheng; Fang, Yaobing^*; Li, Li; Yuan, Wenhui^*

来源：Small, 2023.

DOI：10.1002/smll.202306140

• interlayer
• lithium-sulfur batteries
• metal-organic frameworks
• molybdenum carbide
• synergistic function

The 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 alpha-phase molybdenum carbide nano-crystallites embedded in a porous nitrogen-doped carbon framework (alpha-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 approximate to 5.8 mu L 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.