A Novel Surface Modification Method to Fabricate Silicon/graphene Nanocomposite as Anode Material in Lithium-ion Battery
| Autor: | Han-ping Tseng, 曾翰平 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this research, we proposed a novel surface modification method for the preparation of silicon/graphene composites as anode material for lithium ion battery. Our proposed methodology enables us to formulate a stable suspension of Si nanoparticles in solution with graphene oxides. The proposed process offers an easy, cost-effective and commercialization-compatible system for the current lithium ion battery industry. In order to optimize the anode material conditions, we investigated the effect of the Si content in the composites and the effect of GO reduction temperature. Lastly, we compared our process with literature reports. It demonstrated that without the need of additional steps (chemical functionalization) and the need of additional materials (surfactant modification) the comparable capacity and stability performance can be achieved. The sample prepared from our method delivers a reversible capacity of 1264 mAh/g. The capacity at 30th cycle still retained around 68 % of the initial cycle. To further improve the cycling stability, vinylene carbonate (VC) was added to the electrolyte. Even though the initial capacity of electrode in VC-containing electrolyte is lower, the retained capacity after 40 cycles was about 80 % of the initial cycle. In addition, the coulombic efficiency was also found to be higher than the electrodes without the use of VC. This suggests that the addition of VC can form a more stable SEI layer, resulting in better cycling stability. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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