SOLID BIOPOLYMER ELECTROLYTES DEVELOPMENT BASED ON CELLULOSE DERIVATIVES BLEND DOPED WITH IONIC LIQUID FOR LITHIUM-ION BATTERIES APPLICATION

• Main Author: Theo Constan Lotebulo Ndru, Sun
• Format: Dissertations
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/42667
• Institution: Institut Teknologi Bandung

One of the lithium-ion batteries drmvbacks that have been commercially developed occurs at the using of liquid as electrolytes source. Liquid electrolytes that used in conventional Li-ion batteries are corrosive, volatile and flammable when operated at high temperatures. To overcome the issue of liquid electrolyte utilization. it can be employed by solid polymer electrolytes. Characteristics, environment and cost of production aspects are to be the main altention to develop the biopolymer electrolyte membranes. The combination of ce llulose derivatives blend t echnique and the use of additives of ionic liquid to exhibit the best characteristics in this research is a novelty in polymer electrolyte fields. Increasing of the added value of Indonesia local product waste of pod husk kakao to be cellulose derivative , a polymer electrolyte component , can decrease the cost of production and press environmental problems caused by unfriendly mat erials such as polyethylene ( PE), polypropylene (PP) and polyethylene oxide (PEO). This research studied the characteristics of biopolymer electrolytes from ce llulose derivative blends of commercial methyl cellulose (MC) and carboxymethyl cellulose (CMC) from both commercial microcrystalline cellulose (MCC) and pod husk kakaa [Theobroma cacao L. (TCL)]. Cellulose was isolated from KBK waste from Nias Island, North Sumatera, with microwave-assisted extraction (MAE) method through NaOH treatment at 50 °C for 30 minutes. bleaching temperature 60 °C for 1 hour using H202, with the yields of25. 22%, the average particles size is 561 7,9 nm, the crystallinity index is .:f0.-18%. CMC and MC are important cellulose ethers and ha v ing appealing properTies such as biocompatible. environmentally friendly, good thermal stabilities and good solubilit y in wafer. so they can be applied in various applications, such as polymer elecl rolyre membranes preparation. MC was obtained commercially, while CMC was :,y111hesized from cellulose-KBK. The synthesis of CMC using the MAGS r microwave-assisted organic synthesis) rnethod was conducted at 100 watts, temperature 60 °C for 1 hour. and DS 0.86 from KBK and 1.75 from MCC commercial. Based on the calculation, M, of CMC-MCC and CMC -KBK exhibit 36.-176.56 Do and 21, 251. 28 Do, respectively. Ionic liquids are a type of salt that melts at room temperature or below I 00 °C with have outstanding properties, such as high conductivity, high boiling point, good thermal resistance, etc., which can give a plasticizing effect to the solid polymer electrolyte membrane. A 1-ethyl-3-methylimidazolium acetate, [EM!m}Ac) ionic liquid was used as plasticizers and filler in biopolymer electrolyte system in this study. A 1-ethyl-3-methylimida::.olium bromide, [EM!m}Br ionic liquid was synthesized using MAGS (microwave-assisted organic synthesis) method with 100 watts, a temperature of 50 °Cfor 15 minutes. Meanwhile, the [EM!m}Ac ionic liquid was synthesized through a metathesis reaction between [EM!m}Br ionic liquid and potassium acetate at room temperature for 1 hour. Both of ionic liquids were analyzed by FTIR and NMR to confirm the functional groups and molecular structure. Solid biopolymer electrolyte membranes based on MCICMC blend doped with ionic liquid were conducted using casting solution technique at room temperature. According to ionic conductivities and mechanical properties, selected optimum condition of polyblend membrane to be polymer host to lithium- ion i.e. MCICMC­ MCC (50150), MCICMC-KBK (50150) and MC/CMC-KBK (80/20). The 10% LiC/0., salt introduction as Li-ion sources enhance MCICMC blend membrane ionic conductivities , however. it decreases the mechanical stability, crystallinity index and thermal stability for all compositions. The weakness ofLiCIO., impact to MC/CMC blend polymer host was overcome by ionic liquid incorporation. Presence of [EM!m}Ac ionic liquid (10-15%) improve the mechanical properties and thermal stability of MC/CMC -MCC (50150) blend, MCICMC-KBK (50/20) blend dan MCICMC-KBK (80120) blend significantly, without disturbing their ionic conductivities. All the characteristics of ionic conductivities, mechanical properties and thermal stability 111ere supported by crystallinity analysis and SEM of surface and cross-section morphology in each optimum condition of prepared MCICMC-based solid biopolymer electrolyte. From all of compositions, the best characteristics is MC/CMC-KBK (50150) + 10% LiClO., + 10% [EM/mAc} biopolymer electrolyte membrane. Based on research findings. ionic liquid introduction effect to LiC/04-complexed MCICMC blend produce ideal solid polymer electrolyte characteristics, they are ionic conductivities, good mechanical properties and thermal stability. This work used cellulose derivative-based biopolymer as well as safety and environmentally friendly ionic liquid effectively so that the environmental proble111s overcome. The efficient production process design can be proposed to replace fossil fuel-based .\ynthetic polymer applied as separator and also Li-ion source (elec!rolyte) for Li­ ion balleries application.