MEMBRANE POLYMER ELECTROLYTES OF CARBOXYMETHYL CHITOSAN AND POLYVINYLIDE DIFLORIDE (PVDF) FOR LITHIUM ION BATTERY CELL APPLICATIONS

• Main Author: Maulana Ababil, Azmil
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/52129
• Institution: Institut Teknologi Bandung

The use of lithium ion batteries increases continuously every year, but there are safety concerns about using liquid electrolytes from organic solvents. One alternative solution to this problem is the use of solid phase electrolytes. The solid phase electrolyte can be made from polymers as the base material, and one of them is chitosan. Chitosan is a biopolymer which is abundant in nature and has good mechanical and thermal properties. Because chitosan has a low ionic conductivity, it is necessary to modify it to become carboxymethyl chitosan and by addition of polyvinylidene difluoride (PVdF) and LiClO4. The isolation result of chitosan from shrimp shell waste by deproteination, demineralization, and deacetylation had a deacetylation degree of 68.34% and a yield of 16.68%. Modification of chitosan into carboxymethyl chitosan was carried out by the carboxymethylation process by using monochloroacetic acid to produce a yield of 97.6% and a substitution degree of 0.94. The absorption peak at wave number of 1745 cm-1 in FTIR analysis indicates the formation of a carboxylate functional group on carboxymethyl chitosan. This result is supported by the increasing of ionic conductivity, as well as decreasing of mechanical and thermal properties. While the addition of 15% LiClO4 to chitosan, carboxymethyl chitosan, and a mixture of chitosan and carboxymethyl chitosan, was resulted the best ionic conductivity about 5.57 x 10-3 S/cm in the mixture of carboxymethyl chitosan and LiClO4, and the best mechanical properties of 53.38 MPa in the mixture of carboxymethyl chitosan/chitosan/LiClO4. On the composite membranes of carboxymethyl chitosan/LiCLO4 with the addition of PVdF, appears absorption peaks at wave numbers 878 cm-1 and 1244 cm-1 in the FTIR-ATR spectrum, indicating the presence of vibration from C-F and C-C bonds. The maximum ionic conductivity of 1.40 x10-2 S/cm was obtained in the composite membranes with the addition of PVdF 3% and the maximum tensile strength of 17.24 MPa with the addition of PVdF 1%.