Regulating Ion‐Dipole Interactions in Weakly Solvating Electrolyte towards Ultra‐Low Temperature Sodium‐Ion Batteries

Abstract Sodium‐ion batteries (SIBs) are recognized as promising energy storage devices. However, they suffer from rapid capacity decay at ultra‐low temperatures due to high Na + desolvation energy barrier and unstable solid electrolyte interphase (SEI). Herein, a weakly solvating electrolyte (WSE) with decreased ion‐dipole interactions is designed for stable sodium storage in hard carbon (HC) anode at ultra‐low temperatures. 2‐methyltetrahydrofuran with low solvating power is incorporated into tetrahydrofuran to regulate the interactions between Na + and solvents. The reduced Na + ‐dipole interactions facilitate more anionic coordination in the first solvation sheath, which consistently maintains…

• NN
  National Natural Science Foundation of China

  Awards: 22325902, 52171215