title: Hierarchical Graphene-Encapsulated Hollow SnO2@SnS2 Nanostructures with Enhanced Lithium Storage Capability.
abstract: Complex hierarchical structures have received tremendous attention due to their superior properties over their constitute components. In this study, hierarchical graphene-encapsulated hollow SnO2@SnS2 nanostructures are successfully prepared by in situ sulfuration on the backbones of hollow SnO2 spheres via a simple hydrothermal method followed by a solvothermal surface modification. The as-prepared hierarchical SnO2@SnS2@rGO nanocomposite can be used as anode material in lithium ion batteries, exhibiting excellent cyclability with a capacity of 583 mAh/g after 100 electrochemical cycles at a specific current of 200 mA/g. This material shows a very low capacity fading of only 0.273% per cycle from the second to the 100th cycle, lower than the capacity degradation of bare SnO2 hollow spheres (0.830%) and single SnS2 nanosheets (0.393%). Even after being cycled at a range of specific currents varied from 100 mA/g to 2000 mA/g, hierarchical SnO2@SnS2@rGO nanocomposites maintain a reversible capacity of 664 mAh/g, which is much higher than single SnS2 nanosheets (374 mAh/g) and bare SnO2 hollow spheres (177 mAh/g). Such significantly improved electrochemical performance can be attributed to the unique hierarchical hollow structure, which not only effectively alleviates the stress resulting from the lithiation/delithiation process and maintaining structural stability during cycling but also reduces aggregation and facilitates ion transport. This work thus demonstrates the great potential of hierarchical SnO2@SnS2@rGO nanocomposites for applications as a high-performance anode material in next-generation lithium ion battery technology.
authors.affiliation: Department of Mechanical & Industrial Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Wangwang
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Mechanical & Industrial Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Mechanical & Industrial Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.
authors.forename: Kangning
authors.initials: K
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Mechanical & Industrial Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Grant
authors.initials: G
authors.lastname: Dietrich
authors.affiliation: Department of Chemical Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Kerry M
authors.initials: KM
authors.lastname: Dooley
authors.affiliation: Department of Mechanical & Industrial Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
keywords: anode; graphene; hierarchical nanostructure; lithium ion battery; tin dioxide; tin disulfide