Regulation of anion–Na + coordination chemistry in electrolyte solvates for low-temperature sodium-ion batteries

High-performance sodium storage at low temperature is urgent with the increasingly stringent demand for energy storage systems. However, the aggravated capacity loss is induced by the sluggish interfacial kinetics, which originates from the interfacial Na + desolvation. Herein, all-fluorinated anions with ultrahigh electron donicity, trifluoroacetate (TFA − ), are introduced into the diglyme (G2)-based electrolyte for the anion-reinforced solvates in a wide temperature range. The unique solvation structure with TFA − anions and decreased G2 molecules occupying the inner sheath accelerates desolvation of Na + to exhibit decreased desolvation energy from 4.16 to 3.49 kJ mol −1 and 24.74 to 16.55 kJ mol −1 beyond…

• NN
  National Natural Science Foundation of China

  Awards: 22325902, 52202286, 22309002, 52171215
• CP
  China Postdoctoral Science Foundation

  Award: 2023M730007
• NO
  National Outstanding Youth Science Fund Project of National Natural Science Foundation of China

  Award: 22325902