Hu Zongjie, Yan Gaojie, Zhao Jinchen, Zhang Xiaojie, Feng Yi, Qu Xiongwei, Ben Haijie, Shi Jingjing
Hebei Key Laboratory of Functional Polymers, Department of Polymer Materials and Engineering, Hebei University of Technology, 8 Guangrong Street, Tianjin 300130, People's Republic of China.
College of Chemical & Material Engineering, Quzhou University, Quzhou 324000, People's Republic of China.
Nanotechnology. 2022 Mar 8;33(22). doi: 10.1088/1361-6528/ac54e0.
The practical application of lithium-sulfur battery is seriously limited by the loss of active substances and the deterioration of cycle stability caused by the 'shuttle effect' of lithium polysulfides (LiPSs). In this work, graphene oxide (GO) coated covalent organic framework (COF) compound materials were synthesized as sulfur host material in spray-drying process. The polar groups on COF can efficiently adsorb LiPSs through lithiophilic interaction, which can reduce the 'shuttle effect' caused by soluble LiPSs. Besides, GO in the outer layer can wrap discrete sulfur to reduce the loss of active substances, which further improves the cycle stability of the cathode. The COF@GO/S cathode exhibits a high initial specific capacity of 848.4 mAh gand retains a capacity of 601.1 mAh gafter 500 cycles at 1 C counting with a low capacity fading of 0.058% per cycle.
锂硫电池的实际应用受到多硫化锂（LiPSs）“穿梭效应”导致的活性物质损失和循环稳定性恶化的严重限制。在这项工作中，通过喷雾干燥法合成了氧化石墨烯（GO）包覆的共价有机框架（COF）复合材料作为硫主体材料。COF上的极性基团可通过亲锂相互作用有效吸附LiPSs，从而减少可溶性LiPSs引起的“穿梭效应”。此外，外层的GO可以包裹离散的硫以减少活性物质的损失，这进一步提高了正极的循环稳定性。COF@GO/S正极在1 C下首次放电比容量高达848.4 mAh/g，500次循环后容量保持在601.1 mAh/g，每循环容量衰减率低至0.058%。
