ELECTROLYTIC POLYMER MEMBRANES PREPARED FROM CARBOXYMETHYL CHITOSAN WITH ADDITION OF [BMIM]AC/LI+ IONIC LIQUID FOR LITHIUM JON BATTERY CELL APPLICATION

• Main Author: Pualam, William
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/65261
• Institution: Institut Teknologi Bandung

Cunently a lithium ion battery is one of the necessity of human life, but liquid electrolytes used as ion media and cathode and anode separators have a risk of leakage to explosion, so solid electrolytes in the form of polymer membranes can be a promising alternative, but have poor ion conductivity. as well as liquid electrolytes. Electrolytic membranes from natural biopolymer-s such as chitosan are promising to be used as solid electrolyte polymers by modifying side groups and adding necessary additives. This study aims to isolate chitosan from shrimp shells, then modify it into carboxymethyl chitosan, and make polymer membranes from carboxymethyl chitosan with the addition of ionic liquid, and optimize several parameters based on the proper1ies of the resulting membrane. In this study, carboxymethyl chitosan was used as the polymer matrix with the addition ofliquid [BMim]Ac/Li+ ions which act as plasticizer-s and as a source oflithium ions. Chitosan isolated from shrimp shells has low ionic conductivity, although it has good thermal stability and mechanical proper1ies. Shrimp shell isolation was canied out with demineralization, deproteination, and deacetylation steps to produce chitosan with a degree of deacetylation of 58.48%, which was then carboxymethylated to carboxymethyl chitosan with a substitution degree of 1.24. The ionic liquid used was synthesized from methyl imidazole and butyl chloride precm-sor-s, followed by a metathesis reaction with lithium acetate salt to produce [BMim]Ac/Li+ ionic liquid. The addition of this ionic liquid to the polymer membrane allows the ions to move freely, thereby increasing the ionic conductivity. Electrolytic polymer membranes were made by casting a solution of carboxymethyl cellulose in 2% acetic acid, with the addition of ionic liquid in various compositions and the resulting membranes were characterized to determine its properties such as ionic conductivity, thermal stability, crystallinity, mechanical properties and thermal properties. The optimal membrane based on the ionic conductivity of 1.25 x 10-4 S/cm and its mechanical proper1ies of 1.28 MPa was obtained on a membrane with a composition of0.30-gram carboxymethyl chitosan with the addition of20% (w/w) of ionic liquid, and this membrane has degree of crystallinity of 8.51% and thermally stable up to a temperature of 232°C. This membrane has the potential to be used for lithium ion battery cell applications.