Single Mo–N4 Atomic Sites Anchored on N‐doped Carbon Nanoflowers as Sulfur Host with Multiple Immobilization and Catalytic Effects for High‐Performance Lithium–Sulfur Batteries

Abstract

AbstractRational design of sulfur hosts for effectively confining lithium polysulfides (LiPS) and optimizing the sluggish sulfur kinetics is still a major challenge in lithium–sulfur batteries (LSBs). In this work, a simple strategy of introducing single Mo–N4 atoms into N‐doped carbon nano‐flower matrix (Mo‐N‐CNF) as sulfur host cathode materials is developed to realize high‐performance LSBs. These single Mo–N4 atoms have been demonstrated to regulate the hydrophilic nature, Li‐ion diffusion, adsorption capacity, and catalytic conversion of polysulfides via experimental evidences and theoretical calculations. The resulting Mo‐N‐CNF with high loading content of sulfur (>72 wt.%) exhibits a high specific capacity (1248 mAh g–1 at 0.2 C) and excellent rate capability (715 mAh g–1 at 5 C). More importantly, the outstanding cycling performance with a low attenuation rate of only 0.004% per cycle over 400 cycles at 4.27 mA cm–2 is achieved with the area sulfur loading of 5.1 mg cm–2. This work demonstrates a viable strategy for using single atoms‐based carbon materials with high exposed sites as multiple captors for LiPS and an efficient accelerator for sulfur redox kinetics toward next‐generation LSBs with boosted electrochemical performance.