Modulating Ion‐Dipole and Dipole–Dipole Interactions for Stable Wide‐Temperature‐Range Lithium–Sulfur Batteries Enabled by Quantum‐Dot Catalysts

The incomplete conversion of sulfur species, particularly the pivotal intermediate solid Li$_2$S$_2$ during redox processes, poses a significant limitation on the cyclability of lithium–sulfur batteries (LSBs). Herein, a synergistic modulation strategy of ion-/dipole–dipole interactions that tailors the solvation sheath configuration and activates the electrochemical reactivity of Li$_2$S$_2$ is initially proposed for accelerating kinetics. As a proof of concept, the molybdenum nitride quantum dots located on nitrogen-doped carbon (MoNQDs/NC) were designed. Advanced in situ/ex situ characterizations combined with theoretical calculations reveal that MoNQDs/NC effectively weaken the ion-dipole interactions within Li(solvent)$_x$$^+$ species, thereby facilitating the desolvation process. Furthermore, the robust dipole–dipole interactions between polar domains of MoNQDs and Li$_2$S$_2$ are realized to generate localized tensile strain fields to destabilize the S─S/Li─S bonds network. Consequently, the optimal cells maintain a high areal capacity (>5.0 mAh cm$^{-2}$) after 50 cycles at high sulfur loading (4.4–9.1 mg cm$^{-2}$) over a wide temperature range (0–60 °C). ... mehrFurthermore, the pouch cell with a sulfur loading of 1.5 g retained a capacity of 1.79 Ah after 15 cycles, highlighting the potential of this ion-dipole modulation strategy for commercializing LSBs.