NMR Study on the Synthesis and Optimization of Self-Terminated Oligomers with hyper-Branched Architecture

• Main Authors: Yuan-Chun Wen, 溫源鈞
• Other Authors: Hsi-Wei Jia
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/kfz9mc

博士 === 中原大學 === 化學研究所 === 106 === In recent years, lithium-ion batteries is quickly developing, and it is widely used in many electronic devices, even become an indispensable part of life. With the demand for high power of power batteries, the performance of lithium-ion batteries has made great progress. However, thermal runaway is a potential risk when using lithium-ion batteries. Self-terminating high-density oligomers (STOBA) have been proven to be the most effective electrolyte safe additive for lithium-ion batteries. Therefore, understanding the STOBA formation mechanism will help us to improve the function and application of this safe additive. Nuclear magnetic resonance (NMR) technology can be used as a derivative of STOBA raw material, 4,4''-Bismaleimidodi-phenylmethane (hereinafter referred to as BMI1000) (BMI2300) and Barbituric Acid (hereinafter referred to as BTA) and the STOBA synthesis reaction in the solvent methylpyrrolidone (N-Methyl-2-pyrrolidone, hereinafter abbreviated as NMP) were studied at a molecular level. Surmising the possible reaction mechanism and the bonding of reactants in STOBA synthesis reaction in chemical kinetics in order to speculate STOBA molecular structure and the safety mechanism actuation behavior when STOBA as a safe additive of lithium-ion battery. In the present study, the STOBA synthesis reaction was studied at different elapsed times by a series of NMR experiments during the reaction, and the experiment was repeated at different reactant ratios to confirm the reaction mechanism. The results show that the product of the STOBA synthesis reaction was depending on factors such as solvent, reactant type, concentration, reaction temperature, reaction time, stirring rate, and order of addition. According to NMR and SAXS, SEM, GPC supplemented, we confirmed that the main reaction mechanism of STOBA synthesis consists of two kinds: Michael addition reaction and homopolymerization radical reaction. Two reaction mechanisms competing under different reaction time.