Modulating Ion-Dipole and Dipole-Dipole Interactions for Stable Wide-Temperature-Range Lithium-Sulfur Batteries...

The incomplete conversion of sulfur species, particularly the pivotal intermediate solid Li₂S₂ 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 Li₂S₂ 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 Li₂S₂ 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). Furthermore, 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.