THE EFFECT OF ADDITION NANOCRYSTALLINE CELLULOSE OBTAINED FROM ISOLATION OF CORNCOB ON PROPERTIES OF POLYMER ELECTROLYTE MEMBRANES POLY(VINYL ALCOHOL)/LiClO4

• Main Author: Purwanti, Endah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/38217
• Institution: Institut Teknologi Bandung

The development of renewable energy from the battery that can store large capacity energy will be increased. Lithium ion battery is the best battery to be developed because it has a high energy density and long cycle life, and also it is lighter than lead acid, Ni-Cd, and Ni-MH batteries. Generally, the lithium ion battery uses a liquid electrolyte which has some disadvantages, such as the limited operating temperature range, the frequent occurrence of an explosion and also the cause of electrode corrosion. Therefore, it is necessary to be developed lithium ion battery based on polymer electrolyte membrane to minimize the shortage. The matrix polymer used in this study is poly(vinyl alcohol) (PVA), because it has high mechanical strength, good thermal stability, and relatively cheaper. The polymer electrolyte membrane with PVA as a polymer matrix base material and lithium perchlorate (LiClO4) as an ionic salt in various compositions still has a relatively low ionic conductivity, so it needs to be modified by adding a nanocrystalline cellulose obtained from hydrolysis cellulose of corncob. The aim of this study is to obtain the information about the influence of LiClO4 compositions and the addition of the nanocrystalline cellulose on the characteristics of the resulting polymer electrolyte membrane with PVA base material. Polymer electrolyte membranes were prepared by casting polymer solution of PVA/LiClO4 in various compositions in a solvent of water, and then the polymer electrolyte membrane at an optimum composition of LiClO4 based on ionic conductivity and mechanical properties was added the nanocrystalline cellulose in various compositions, so it is expected to obtain optimum polymer electrolyte membrane for lithium battery application. Based on infrared data, the pattern of infrared absorption for the polymer electrolyte membrane of PVA/LiClO4 in various compositions of LiClO4 are not different significantly, and also for the polymer electrolyte membrane of PVA/LiClO4 after the addition of the nanocrystalline cellulose in various compositions. However, it was observed the presence of several shifts the absorption peaks with the different intensity of absorption. These results indicate that the interaction between the PVA with Li ion on the polymer electrolyte membrane PVA/LiClO4 as well as between PVA, Li, and nanocrystalline cellulose on the electrolyte membrane PVA/LiClO4/nanocrystalline cellulose tends to occur physical interaction through the interaction between the -OH groups of PVA with Li+ ion from LiClO4 or with -OH groups of nanocrystalline cellulose. The optimum condition of polymer electrolyte membrane PVA/LiClO4 based on ionic conductivity and mechanical properties was obtained in the membrane composition of the PVA/LiClO4 at 85/15 (% w/w) with ionic conductivity of 4,82 x 10-5 S/cm, tensile stress of 39,71 MPa, strain of 609,15 %, and modulus at break value of 0,065 MPa. While the polymer electrolyte membrane of PVA/LiClO4 after the addition of the nanocrystalline cellulose, the optimum condition was obtained in membranes with the composition of 80/15/5 (w/w) (PVA/LiClO4/nanocrystalline cellulose) with ionic conductivity of 1,66 x 10-4 S/cm, tensile stress of 36,64 MPa, strain of 700,59 %, and modulus at break value of 0,052 MPa. Based on the analysis of TGA thermogram, the polymer electrolyte membrane synthetized with the composition of 80/15/5 (PVA/LiClO4/nanocrystalline cellulose) is relatively thermally stable up to a temperature of 252 °C. The addition of small amounts of nanocrystalline cellulose can improve the ionic conductivity and mechanical properties of the membrane, but it practically is not change the thermal stability of the membrane. Therefore, the polymer electrolyte membrane of PVA/LiClO4/nanocrystalline cellulose can be potentially used as a polymer electrolyte membrane for the lithium ion battery application.