Formation mechanism of porous spheres and their applications in lithium-sulfur battery
| Autor: | Chang-Ju Hsieh, 謝昌儒 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Lithium-sulfur batteries are considered a great prospect for energy storage purpose, courtesy to high theoretical specific capacity of sulfur (1672 mAh/g). However, due to shuttling effect of lithium polysulfides, these batteries show poor cycle life. In this study, to improve the performance, conductive polymers and porous carbon spheres are used. While the nitrogen atom of conductive polymers can bind polysulfides during charging and discharging, the porous carbon spheres with high quality of morphologies can provide better space to improve poor conductivity and expansion of sulfur. Higher capacity and better cycle life are achieved by the synergic effect of both the materials as it increases the utilization of sulfur and prevents the dissolution of polysulfides in the electrolyte. The sulfur-conductive polymers/porous carbon spheres composite material is characterized by infrared spectroscopy and scanning electron microscope. The sulfur content is quantified by thermogravimetric analysis. Electrochemical measurements show a better discharge capacity for the synthesized composite electrode (1234 mAh/g) compared to the blank sulfur composite electrode (1110 mAh/g), at a 0.05C- discharging rate. The cycle life of the composite electrode is also better than that of the blank. The results demonstrate that the composite electrode material can improve the performance of lithium-sulfur battery. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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