Modulating Ion‐Dipole and Dipole–Dipole Interactions for Stable Wide‐Temperature‐Range Lithium–Sulfur Batteries Enabled by Quantum‐Dot Catalysts
Yongqian He, Duanfeng Xiong, Manfang Chen, Wanqi Zhang, Sisi Liu, Yongjie Ye, Mengqing Wang, Ying Chen, Qin Tang, Xuewen Peng, Caixiang Wang, Hongyang Zhan, Hong Liu, Min Liu, Jincang Su, Hongbo Shu, Jian Wang, Xianyou Wang
Abstract
Abstract 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). 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.