Improved sodium-storage performance of stannous sulfide@reduced graphene oxide composite as high capacity anodes for sodium-ion batteries

摘要

Stannous sulfide@reduced graphene oxide (SnS@RGO) composite is successfully synthesized via a facile precipitation route. The structural and morphological characterizations reveal SnS@RGO composites are composed of SnS nanoparticles of the size 5-10 nm, which are uniformly anchored on the surface of RGO. The electrochemical measurements demonstrate the reversible capacity of the SnS@RGO composite that includes contributions from the conversion reaction of SnS to Sn and NaxS and the alloying reaction of Sn to NaxSn. The SnS@RGO electrode exhibits a reversible capacity of 457 mAh g(-1) at 20 mA g(-1) superior cycling stability (94% capacity retention over 100 cycles at 100 mA g-1) and adequate rate performance. Compared to the neat SnS nanoparticles, the enhanced electrochemical performance of the SnS@RGO composite is primarily due to the incorporation of RGO as a highly conductive, flexible component as well as possessing a large available surface area, which provides desirable properties such as improved electronic contact between active materials, aggregation suppression of intermediate products, and alleviation of the volume change during sodiation and desodiation. Encouraging experimental results suggest that the SnS@RGO composite is a promising material to achieve a high-capacity and stable anode for NIBs. (C) 2015 Elsevier B.V. All rights reserved.