title: Facile Hydrothermal Synthesis of VS2/Graphene Nanocomposites with Superior High-Rate Capability as Lithium-Ion Battery Cathodes.
abstract: 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(-1) after 200 cycles at 0.2 C. Even at 20 C, the composites still deliver a high capacity of 114.2 mAh g(-1) 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(-1) capacity after 100 cycles at 200 mA g(-1). 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.
authors.affiliation: †Department of Chemistry, College of Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, People's Republic of China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Fang
authors.affiliation: †Department of Chemistry, College of Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, People's Republic of China.|‡Department of Chemical Engineering, University of Waterloo, 200 University Ave. West, Waterloo N2L 3G1, Canada.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: †Department of Chemistry, College of Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, People's Republic of China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Xie
authors.affiliation: †Department of Chemistry, College of Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, People's Republic of China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Fang
authors.affiliation: †Department of Chemistry, College of Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, People's Republic of China.
authors.forename: Jiaqiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: ‡Department of Chemical Engineering, University of Waterloo, 200 University Ave. West, Waterloo N2L 3G1, Canada.
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Chen
keywords: cathode materials; graphene; layered-VS2; lithium ion batteries; transition metal dichalcogenides