期刊
ELECTROCHIMICA ACTA
卷 296, 期 -, 页码 155-164出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.electacta.2018.11.040
关键词
Lithium-sulfur batteries; Carbon-nanotube-based sulfur cathodes; Polysulfides; Shuttle effect; Silicon nitride interlayers
资金
- China Postdoctoral Science Foundation [2016M592795]
- Natural Science Foundation of Shaanxi Province, China [2017ZDJC-30, 2018JQ2027]
- Key Research Project of Shaanxi Province, China [2018ZDCXL-GY-08-06]
- Natural Science Foundation of Jiangsu Province, China [BK20170413]
- Fundamental Research Funds for the Central Universities, China [xjj2017084]
A Si3N4/graphene composite is designed as an interlayer for a carbon-nanotubes/sulfur cathode to improve electrochemical performance of lithium-sulfur batteries. In the interlayer, Si3N4 nanoparticles suppress the migration of the dissolved polysulfides and graphene sheets construct a 3-dimensional charge-transfer network. The carbon-nanotubes/sulfur@Si3N4/graphene cathode delivers an initial discharge capacity of 1334.7 mAh g(-1) at 0.1 C and retains a capacity as high as 745.8 mAh g(-1) after 200 cycles, with a capacity fade ratio of 0.22% per cycle. The cathode shows good cycling life, delivering a discharge capacity of 413.3 mAh g(-1) for 1 C after 1000 cycles. According to the results of density functional theory calculation, the anchoring of the Si3N4/graphene interlayer to lithium polysulfide can be attributed to a coefficient chemical binding of Li-N and Si-S bonds generating from electronic conjugation effect between the Si3N4 supercell surface and the polysulfides. Generally, the improvement in electrochemical performance originates from the enhancements in Li+ diffusion coefficient and charge transfer, and from the restraining of the shuttle effect of the dissolved lithium polysulfide as a result of the Si3N4/graphene interlayer. (C) 2018 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据