POLYMER ELECTROLYTE MEMBRANE OF POLI(ETHYLENE OKSIDE) DOPED IONIC LIQUID 1-ETHYL-3-METHYLIMIDAZOLIUM-TETRAFLUOROBORATE (EMImBF4)/Li+ FOR LITHIUM-ION BATTERY APPLICATION

• Main Author: Theo Constan Lotebulo N, Sun
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/32767
• Institution: Institut Teknologi Bandung

Energy storage battery demand, especially for portable electronics are elevated. As storage cells, lithium-ion battery is in great favor because it has high energy density, long life cycle and rechargeable. However, lithium-ion battery also has drawbacks because of the use of liquid electrolytes which are corrosive and volatile, that would cause leakage and explosion during rechargeable process at high temperature. To overcome these problems is to change liquid electrolyte to solid electrolyte that is polymer electrolyte. Polymer electrolyte also functions as separator which boundaries compartement both anode and cathode. In this research, the polymer electrolyte was made by casting poly(ethylene oxide) (PEO) and doped with ionic liquid. PEO is easy to be modified, but it has high crystalline properties. Ionic liquids have high conductivity and boiling point and have good thermal stability. In this study, ionic liquid embedded with Li+ ion, which is 1-etyl-3-metylimidazolium-tetrafluoroborate (EMImBF4)/Li+, was synthesized using metathesis reaction between 1-ethyl-3-methylimidazolium-bromide (EMImBr) and LiBF4 salt. EMImBr was previously synthesized from 1-methylimidazole and bromoethane using Microwave Assisted Organic Synthesis (MAOS) method. The structures of synthesized EMImBr and EMImBF4/Li+ were confirmed by FTIR and NMR spectra analysis. Polymer electrolyte membrane was prepared by casting ionic liquid EMImBF4/Li+ and PEO using various percentage of mass ratios of EMImBF4/Li+ added to PEO. The characteristics of polymer electrolyte membrane PEO – ionic liquid EMImBF4/Li+ have been confirmed by the analysis of fuctional groups, structure elucidation, ionic conductivity, mechanical properties, thermal stability, crystallinity, and morfology of membrane. Electrochemical Impedance Spectroscopy (EIS) analysis showed that polymer electrolyte membrane contained 16% mass of EMImBF4/Li+ has the highest ionic conductivity, which is 1.83 x 10-3 S cm-1. The high value of ionic conductivity was assumed to be caused by the free mobilisation of ions, especially Li+ ions, through the amorphous state of polymer electrolyte membrane pores, which has been confirmed by mechanical properties, crystallinity, morphology images data and thermal analysis.