Cobalt-doping SnS2 nanosheets towards high-performance anodes for sodium ion batteries

• Published in: Nanoscale 2020-01, Vol.12 (1), p.248-255
• Main Authors: Wang, Liqin, Zhao, Quanqing, Wang, Zhitao, Wu, Yujun, Ma, Xilan, Zhu, Youqi, Cao, Chuanbao
• Format: Article
• Language: English
• Subjects: Anode effect; Cloth; Doping; Electrochemical analysis; Electrode materials; Interlayers; Nanosheets; Rechargeable batteries; Sodium-ion batteries; Substrates; Tin disulfide
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr07849e

Layered SnS2 is considered as a promising anode candidate for sodium-ion batteries yet suffers from low initial coulombic efficiency, limited specific capacity and rate capability. Herein, we report a cobalt metal cation doping strategy to enhance the electrochemical performance of a SnS2 nanosheet array anode through a facile hydrothermal method. Benefitting from this special structure and heteroatom-doping effect, this anode material displays a high initial coulombic efficiency of 57.4%, a superior discharge specific capacity as high as 1288 mA h g−1 at 0.2 A g−1 after 100 cycles and outstanding long-term cycling stability with a reversible capacity of 800.4 mA h g−1 even at 2 A g−1. These excellent performances could be ascribed to the Co-doping effect that can increase the interlayer spacing, produce rich defects, regulate the electronic environment and improve conductivity. Besides, a carbon cloth substrate can maintain the integrity of the electrode material framework and buffer its volume variation, thus boosting intrinsic dynamic properties and enhancing sodium storage performance.