A 3D Nitrogen-Doped Graphene/TiN Nanowires Composite as a Strong Polysulfide Anchor for Lithium-Sulfur Batteries with Enhanced Rate Performance and High Areal Capacity

作者：Li, Zhaohuai; He, Qiu; Xu, Xu^*; Zhao, Yan; Liu, Xiaowei; Zhou, Cheng; Ai, Dong; Xia, Lixue; Mai, Liqiang^*

来源：Advanced Materials, 2018, 30(45): 1804089.

DOI：10.1002/adma.201804089

• chemical anchoring
• high areal capacity
• lithium-sulfur batteries
• TiN nanowires

Lithium-sulfur (Li-S) batteries have attracted remarkable attention due to their high theoretical capacity of 1675 mAh g(-1), rich resources, inexpensiveness, and environmental friendliness. However, the practical application of the Li-S battery is hindered by the shuttling of soluble lithium polysulfides (LiPSs) and slow redox reactions. Herein, a 3D nitrogen-doped graphene/titanium nitride nanowires (3DNG/TiN) composite is reported as a freestanding electrode for Li-S batteries. The highly porous conductive graphene network provides efficient pathways for both electrons and ions. TiN nanowires attached on the graphene sheets have a strong chemical anchor effect on the polysulfides, which is proved by the superior performance and by density functional theory calculations. As a result, the 3DNG/TiN cathode exhibits an initial capacity of 1510 mAh g(-1) and the capacity remains at 1267 mAh g(-1) after 100 cycles at 0.5 C. Even at 5 C, a capacity of 676 mAh g(-1) is reached. With a high sulfur loading of 9.6 mg cm(-2), the 3DNG cathode achieves an ultrahigh areal capacity of 12.0 mAh cm(-2) at a high current density of 8.03 mA cm(-2). This proposed unique structure gives a bright prospect in that high energy density and high power density can be achieved simultaneously for Li-S batteries.

• 出版日期2018-11
• 单位材料复合新技术国家重点实验室; 硅酸盐建筑材料国家重点实验室; 武汉理工大学