Effect of Zwitterionic Additive on Electrode Protection through Electrochemical Performances of Anatase TiO 2 Nanotube Array Electrode in Ionic Liquid Electrolyte.

In this work, a functionalized zwitterionic (ZI) compound 1-butylsulfonate-3-methylimidazole (C 1 C 4 imSO 3 ) was synthesized and tested as an additive to LiTFSI/C 2 C 2 imTFSI ionic liquid-based electrolytes for lithium-ion batteries. The structure and purity of C 1 C 4 imSO 3 were confirmed by NMR and FTIR spectroscopy. The thermal stability of the pure C 1 C 4 imSO 3 was examined by simultaneous thermogravimetric-mass spectrometric (TG-MS) measurements and differential scanning calorimetry (DSC). The LiTFSI/C 2 C 2 imTFSI/C 1 C 4 imSO 3 system was tested as a potential electrolyte for lithium-ion batteries by using anatase TiO 2 nanotube array electrode as the anode material. This electrolyte with 3% C 1 C 4 imSO 3 showed significant improvement of lithium-ion intercalation/deintercalation properties, such as capacity retention and Coulombic efficiency compared to electrolyte without additive.