Donor Numbers for Ionic Liquids and Carbonate Solvents Using 7Li and 23Na as Probes
摘要
Lithium-ion batteries (LIBs) currently dominate the commercial rechargeable battery market due to their high ionic conductivity and moderate compatibility. To enhance the development and safety of future LIBs, ionic liquids (ILs) have been introduced as additives. For the first time, we present the Lewis acid/base responses of nine ILs in terms of donor number (DN), calculated using 7Li NMR spectroscopy. The anionic component of the ILs significantly influences the DN through its interaction with lithium ions. In addition, the DN of three carbonate solvents was determined using both 7Li and 23Na NMR spectroscopy, showing that DN of solvent is affected by the probe ion and solvent structure. These findings offer valuable insights for selecting appropriate solvents for future electrolyte development in LIBs.