Effect of Zwitterionic Additive on Electrode Protection through Electrochemical Performances of Anatase TiO Nanotube Array Electrode in Ionic Liquid Electrolyte.

In this work, a functionalized zwitterionic (ZI) compound 1-butylsulfonate-3-methylimidazole (CCimSO) was synthesized and tested as an additive to LiTFSI/CCimTFSI ionic liquid-based electrolytes for lithium-ion batteries. The structure and purity of CCimSO were confirmed by NMR and FTIR spectroscopy. The thermal stability of the pure CCimSO was examined by simultaneous thermogravimetric-mass spectrometric (TG-MS) measurements and differential scanning calorimetry (DSC). The LiTFSI/CCimTFSI/CCimSO system was tested as a potential electrolyte for lithium-ion batteries by using anatase TiO nanotube array electrode as the anode material. This electrolyte with 3% CCimSO showed significant improvement of lithium-ion intercalation/deintercalation properties, such as capacity retention and Coulombic efficiency compared to electrolyte without additive.