Insight to the synergistic effect of N-doping level and pore structure on improving the electrochemical performance of sulfur/N-doped porous carbon cathode for Li-S batteries
| Autor: | Yuanfu Deng, Lei Zhang, Shanxing Wang, Yunxian Qian, Kaixiang Zou, Guohua Chen |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Nanocomposite
Materials science chemistry.chemical_element 02 engineering and technology General Chemistry Electrolyte Microporous material 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Nitrogen Cathode 0104 chemical sciences law.invention Chemical engineering Surface-area-to-volume ratio chemistry law Specific surface area General Materials Science 0210 nano-technology |
| Zdroj: | Carbon. 144:745-755 |
| ISSN: | 0008-6223 |
| DOI: | 10.1016/j.carbon.2018.12.113 |
| Popis: | Three nitrogen-doped porous carbons (NDPCs) with the ultrahigh specific surface areas are prepared via a one-step activation of the biomass waste. The as-prepared samples have different levels of nitrogen contents and pore structure. These sulfur hosting matrix materials are designed to systematically elaborate the effect of N-doping level and pore structure on the electrochemical performance of the S/NDPC nanocomposites. The higher volume ratio of marco-mesopores to micropores of the substrate can greatly enhance the rate capability of the S/NDPC cathodes. This is attributed to the improved electrolyte penetration via the rich marco-mesopores. Meanwhile, the higher nitrogen content of the NDPC contributes to improving the cycle stability of the S/NDPC cathode, which is assigned to the strong chemical adsorption and physical restriction of polysulfides by the interaction of nitrogen atom and polysulfides. Therefore, the S/NDPC-1 cathode, prepared by using a NDPC matrix with high nitrogen content, large specific surface area, and a moderate microporous volume percentage (VMicro/VT), displays an obvious enhancement in the electrochemical performance. It exhibits specific capacities of 926.1 and 815.8 mAh g−1 at 0.5 and 1.0 C rate, respectively, with a capacity fading rate of only 0.067% per cycle after 500 cycles at 1.0 C. |
| Databáze: | OpenAIRE |
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