Liu Jie, Li Yanyan, Xuan Yuxue, Zhou Liujiang, Wang Dong, Li Zhenwei, Lin Haifeng, Tretiak Sergei, Wang Hui, Wang Lei, Guo Ziyang, Zhang Shanqing
Taishan Scholar Advantage and Characteristic Discipline Team of Eco-Chemical Process and Technology, State Key Lab Base of Eco-Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
ACS Appl Mater Interfaces. 2020 Apr 15;12(15):17592-17601. doi: 10.1021/acsami.0c00537. Epub 2020 Apr 2.
Because of the severe shuttle effect of polysulfides, achieving durable Li-S batteries is still a great challenge, especially under practical operation conditions including the high sulfur content, high loading, and high operation temperature. Herein, for the first time, low-cost, eco-friendly, and hydrophilic cellulose nanocrystals (CNCs) are proposed as a multifunctional polysulfide stopper for Li-S batteries with high performance. CNCs display an intrinsically high aspect ratio and a large surface area and contain a large amount of hydroxyl groups offering a facile platform for chemical interactions. Density functional theory calculations suggest that the electron-rich functional groups on CNCs deliver robust binding energies with polysulfides. In this work, CNCs not only firmly confine sulfur and polysulfides in the cathode as a robust binder, but also further hinder polysulfide shuttling to the Li anode as a polysulfide stopper on a separator. Consequently, the as-prepared Li-S batteries demonstrate outstanding cycling performance even under the conditions of high sulfur content of 90 wt % (63 wt % in the cathode), high loading of 8.5 mg cm, and high temperature of 60 °C. These results sufficiently demonstrate that CNCs have significant application potential in Li-S battery technologies.
