STUDY OF IONIC CONDUCTIVITY OF IONIC LIQUID BASED IMIDAZOLIUM FOR LITHIUM ION BATTERY

• Main Author: NURUL SHELNI ROFIKA - NIM: 20215003, RIDA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30442
• Institution: Institut Teknologi Bandung

<p align="justify">Ionic liquid are often named solvent of the future to replace carbonate for safer lithium ion battery. Ionic liquid based electrolyte 1-Buthyl-3 methylimidazolium bis trifluoromethylsulfonyl imide (BMIMTFSI) as a solvent of Lithium bis trifluoromethylsulfonyl imide (LiTFSI) salt has studied the relation of salt concentration to ionic conductivity value. Ionic conductivity decrease almost linierly with increases of LiTFSI salt consentration, because of increases of viscosity that slower ionic mobility. The effect of addition of aceonitrile (ACN) changed coordination environment of Li gradually from Li-TFSI to Li-ACN with an increase in the consentration of ACN thus improving ionic conductivity. The highest ion conductivity value is obtained by 1m LiTFSI-1m ACN/BMIMTFSI mixture at 8.4x10-4 S/cm. Lithum half-cell employed LiFePO4 cathode used the elctrolyte has discharge capacity of 39.45 mAh/g at first cycle with coulombic efficiency of 90.62%. Then decrease until 4th cycle with discharge capacity of 31.01 mAh/g and coulombic efficiency of 71.54%. The battery used slow rate because of complex diffusion problem in ionic liquid system. The addition of ACN has been shown to assist the diffusion process of lithium ions. Passivation layer formed from chemical reaction of ions also responsible with the decreases of discharge capacity.<p align="justify">