The Application of multinuclear NMR technology for the Determination of the Spatial Relationship among Carbonate molecules and Li ion in a Li ion electrolyte
| Autor: | Hong-Yi Chen, 陳弘逸 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Lithium-ion batteries are commonly used in a variety of electronic devices. With the increasing demand for high-power batteries, electrolytes play an important role in Li-ion batteries such as conductivity, frost resistance and safety. Therefore, understanding of the spatial relationship among carbonates and Li salt in the electrolyte, that can help us understand the properties of electrolytes. The use of NMR technologies, such as 1H, 13C and 17O chemical shift difference value, ware used to determine the spatial relationship among carbonates and Li salt in the electrolyte. The experimental results show that the electrolyte conforms to the model of ionic atmosphere, forming cation as the center, the outer layer of carbonate, and the anion surrounding the outermost layer. The inductive effect of the cation and the shielding effect of the anion, change the electron density of the carbonate, thereby changing the chemical shift value.A series of different carbonate molar ratio Li ion electrolytes, analysis of 13C, 17O chemical shift difference value, determine the spatial relationship among carbonates and Li salt in the electrolyte. Three-component Li ion electrolyte, 1.2 M LiClO4 in DEC-EC-PC, the spatial relationship is center for Li ion, outer for carbonate according to EC, PC, DEC arrangement. In this study, the spatial relationship among carbonates and Li salt in the electrolyte is closely related to the dielectric constant of the carbonate. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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