Facile Hydrothermal Synthesis of VS2/Graphene Nanocomposites with Superior High-Rate Capability as Lithium-Ion Battery Cathodes

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• 作者：Wenying Fang ; Hongbin Zhao ; Yanping Xie ; Jianhui Fang ; Jiaqiang Xu ; Zhongwei Chen
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：June 17, 2015
• 年：2015
• 卷：7
• 期：23
• 页码：13044-13052
• 全文大小：602K
• ISSN：1944-8252

文摘

In this study, a facile one-pot process for the synthesis of hierarchical VS₂/graphene nanosheets (VS₂/GNS) composites based on the coincident interaction of VS₂ and reduced graphene oxide (rGO) sheets in the presence of cetyltrimethylammonium bromide is developed for the first time. The nanocomposites possess a hierarchical structure of 50 nm VS₂ sheets in thickness homogeneously anchored on graphene. The VS₂/GNS nanocomposites exhibit an impressive high-rate capability and good cyclic stability as a cathode material for Li-ion batteries, which retain 89.3% of the initial capacity 180.1 mAh g^鈥? after 200 cycles at 0.2 C. Even at 20 C, the composites still deliver a high capacity of 114.2 mAh g^鈥? corresponding to 62% of the low-rate capacity. Expanded studies show that VS₂/GNS, as an anode material, also has a good reversible performance with 528 mAh g^鈥? capacity after 100 cycles at 200 mA g^鈥?. The excellent electrochemical performance of the composites for reversible Li⁺ storage should be attributed to the exceptional interaction between VS₂ and GNS that enabled fast electron transport between graphene and VS₂, facile Li-ion diffusion within the electrode. Moreover, GNS provides a topological and structural template for the nucleation and growth of two-dimensional VS₂ nanosheets and acted as buffer matrix to relieve the volume expansion/contraction of VS₂ during the electrochemical charge/discharge, facilitating improved cycling stability. The VS₂/GNS composites may be promising electrode materials for the next generation of rechargeable lithium ion batteries.