A Few-Layer SnS2/Reduced Graphene Oxide Sandwich Hybrid for Efficient Sodium Storage

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• 作者：Fengzhang Tu ; Xin Xu ; Pengzi Wang ; Ling Si ; Xiaosi ZhouJianchun Bao
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：February 16, 2017
• 年：2017
• 卷：121
• 期：6
• 页码：3261-3269
• 全文大小：724K
• ISSN：1932-7455

文摘

Rechargeable sodium-ion batteries have lately received considerable attention as an alternative to lithium-ion batteries because sodium resources are essentially inexhaustible and ubiquitous around the world. Despite recent reports on cathode materials for sodium-ion batteries have shown electrochemical activities close to their lithium-ion counterparts, the major scientific challenge for sodium-ion batteries is to exploit efficient anode materials. Herein, we demonstrate that a hybrid material composed of few-layer SnS₂ nanosheets sandwiched between reduced graphene oxide (RGO) nanosheets exhibits a high specific capacity of 843 mAh g^–1 (calculated based on the mass of SnS₂ only) at a current density of 0.1 A g^–1 and a 98% capacity retention after 100 cycles when evaluated between 0.01 and 2.5 V. Employing ex situ high-resolution transmission electron microscopy and selected area electron diffraction techniques, we illustrate the high specific capacity of our anode through a 3-fold mechanism of intercalation of sodium ions along the ab-plane of SnS₂ nanosheets and the subsequent formation of Na₂S₂ and Na₁₅Sn₄ through conversion and alloy reactions. The existence of RGO nanosheets in the hybrid material functions as a flexible backbone and high-speed electronic pathways, guaranteeing that an appropriate resilient space buffers the anisotropic dilation of SnS₂ nanosheets along the ab-plane and c-axis for stable cycling performance.