Hierarchical Graphene-Encapsulated Hollow SnO2@SnS2 Nanostructures with Enhanced Lithium Storage Capability

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• 作者：Wangwang Xu ; Zhiqiang Xie ; Xiaodan Cui ; Kangning Zhao ; Lei Zhang ; Grant Dietrich ; Kerry M. Dooley ; Ying Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：October 14, 2015
• 年：2015
• 卷：7
• 期：40
• 页码：22533-22541
• 全文大小：500K
• ISSN：1944-8252

文摘

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.