### 三维氮掺杂碳纳米带的制备及其在锂硫电池中的应用

1. a 中国科学院苏州纳米技术与纳米仿生研究所 国际实验室 苏州 215123;
b 清华大学物理系 北京 100084
• 投稿日期:2016-08-25 修回日期:2016-12-05 发布日期:2016-12-05
• 通讯作者: 张跃钢,E-mail:ygzhang2012@sinano.ac.cn;Tel:0512-62872772 E-mail:ygzhang2012@sinano.ac.cn
• 基金资助:

项目受国家自然科学基金（Nos.21433013，51402345，21403287）和苏州市科技计划项目（Nos.ZXG2013002，SYG201532）资助.

### Preparation of Three-dimensional Nitrogen-doped Carbon Nanoribbon and Application in Lithium/Sulfur Batteries

Li Wanfeia, Ma Qiana, Zheng Zhaozhaoa, Zhang Yueganga,b

1. a i-Lab, Suzhou Institute of Nano-Tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123;
b Department of Physics, Tsinghua University, Beijing, 100084
• Received:2016-08-25 Revised:2016-12-05 Published:2016-12-05
• Contact: 10.6023/A16080434 E-mail:ygzhang2012@sinano.ac.cn
• Supported by:

Project supported by the Natural Science Foundation of China (Nos. 21433013, 51402345, 21403287), and the Suzhou Science and Technology Development Program (Nos. ZXG2013002, SYG201532).

Lithium/sulfur (Li-S) batteries have recently attracted intensive research interests due to their high theoretical specific energy of 2600 W·h·kg-1. However, the poor electronic conductivity of sulfur and the high solubility of polysulfides in organic electrolytes lead to poor cycling stability and rate capability. Herein, we report a three-dimensional (3D) nanocomposite network made from nitrogen-doped carbon nanoribbon (NCNB) and nitrogen-doped graphene (NG), which has a high electronic conductivity and can serve as a conductive matrix and a sulfur immobilizer for the sulfur cathode. The NCNB is prepared by thermal nitridation of a unique 3D phenolic resin (PHF) isolated from the polycondensation reaction of 1,4-hydroquinone and formaldehyde. The N content of NCNB-NG can reach as high as 9.7 wt%. Although three types of N bonding geometries, including pyridinic N, pyrrolic N, and graphitic N, are identified in the NCNB-NG composites, we found the pyridinic N is dominant, which facilitates the trapping of intermediate lithium polysulfides. The sulfur was loaded on NCNB-NG by using a Na2S2O3 solution as sulfur source. The scanning electron microscope (SEM) images show that almost no large S particle can be observed in the as-prepared S@NCNB-NG nanocomposites, suggesting a uniform coating of S on the NCNB-NG networks. The transmission electron microscopic (TEM) images and the elemental mapping by Energy-Dispersive X-ray (EDX) analysis also show that nano-sized S particles are uniformly distributed on the NCNB-NG matrix. The as-obtained S@NCNB-NG cathode can deliver a high specific capacity of 1338 mA·h·g-1 at 0.05 C with about 80% S utilization. It also exhibits excellent rate capability and good cycle stability with a retained specific capacity of 556 mA·h·g-1 after 300th cycles. These performances are much higher than the control samples using the S@NCNB and the S@PHF nanocomposites as cathodes. The improved performance can be attributed to the unique microstructure and the improved electronic conductivity of the NCNB-NG matrix.