Wang Donghuang, Xia Xinhui, Wang Yadong, Xie Dong, Zhong Yu, Wu Jianbo, Wang Xiuli, Tu Jiangping
State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and, Applications for Batteries of Zhejiang Province, and School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, P. R. China.
School of Engineering, Nanyang Polytechnic, 569830, Singapore, Singapore.
Chemistry. 2017 Aug 16;23(46):11169-11174. doi: 10.1002/chem.201702779. Epub 2017 Jul 27.
Construction of a novel matrix with both high conductivity and an excellent confinement effect for polysulfides is of great importance for developing high-performance lithium-sulfur (Li-S) batteries. In this work, we have developed a double-modification strategy to integrate lithium sulfide (Li S) into a conductive composite network consisting of vertical graphene (VG) arrays and an amorphous carbon shell, forming an integrated cathode (VG/Li S-C). Facile liquid-solution/evaporation methods in combination with chemical vapor deposition were successfully adopted for preparation of the above cathode. Due to the enhanced electrical conductivity and noticeable blocking effect for the shuttle of polysulfides, the binder-free flexible VG/Li S-C cathode exhibits high rate performance and reinforced cycles (656.2 mAh g after 100 cycles). The pronounced electrochemical performance is ascribed to the unique architecture with a coherent conductive network of VG and the carbon shell, which not only provides a conductive network for fast reaction kinetics, but also forms a durable protective shield to suppress the shuttle of polysulfides. Our research further demonstrates the synergistic effectiveness by means of inner and outer carbon matrixes for electrochemical enhancement of Li-S batteries.
构建一种对多硫化物具有高导电性和优异限制效应的新型基体，对于开发高性能锂硫（Li-S）电池至关重要。在这项工作中，我们开发了一种双重改性策略，将硫化锂（Li₂S）整合到由垂直石墨烯（VG）阵列和非晶碳壳组成的导电复合网络中，形成一种集成阴极（VG/Li₂S-C）。通过简便的液相/蒸发方法与化学气相沉积相结合，成功制备了上述阴极。由于增强的电导率和对多硫化物穿梭的显著阻挡效应，无粘结剂的柔性VG/Li₂S-C阴极表现出高倍率性能和强化循环性能（100次循环后为656.2 mAh g⁻¹）。显著的电化学性能归因于具有VG和碳壳连贯导电网络的独特结构，其不仅为快速反应动力学提供了导电网络，还形成了持久的保护屏蔽以抑制多硫化物的穿梭。我们的研究进一步证明了通过内外碳基体实现锂硫电池电化学增强的协同有效性。
