Pomegranate-like mesoporous microspheres assembled by N-doped carbon coated Fe1−xS nanocrystals for high-performance lithium storage

• Published in: Journal of alloys and compounds 2019-08, Vol.797, p.952-960
• Main Authors: Xu, Xiaoxia, Ma, Quanning, Zhang, Zhonghua, Peng, Hongrui, Liu, Jing, Mao, Changming, Li, Guicun
• Format: Article
• Language: English
• Subjects: Anode material; Anodes; Carbon; Electrical resistivity; Electrode materials; Electron diffusion; Fe1−xS@NC composites; Lithium; Lithium ion batteries; Microspheres; Nanocrystals; Pomegranate-like architecture; Sulfidation; Ultrafines
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.05.222

Uniform pomegranate-like mesoporous Fe1−xS@N-doped carbon microspheres (Fe1−xS@NC) organized by ultrafine Fe1−xS nanocrystal subunits (diameter∼11.9 nm) were prepared via a facile solvothermal process and subsequent sulfidation. In such pomegranate-like mesoporous Fe1−xS@NC, the ultrafine Fe1−xS nanocrystal subunits were embedded within N-doped carbon outer shell, not only shortening Li+/electron diffusion pathways for electrochemical reaction and increasing the electrical conductivity to boost rate capability, but also efficiently preventing ultrafine Fe1−xS subunits from self-accumulation to prolong their cycle life during the electrochemical reaction. Correspondingly, the pomegranate-like Fe1−xS@NC composites manifested excellent cycling stability of 689.8 mAh g−1 after 150 cycles, a high discharge capacity of 1358.3 mAh g−1 at 0.1 A g−1, and superior rate capability of 666.0 mAh g−1 at 5 A g−1 as an anode material for LIBs. [Display omitted] •Fe1-xS@NC composites are synthesized via a facile method.•Fe1-xS@NC composites possess pomegranate-like architecture.•Fe1-xS@NC composites exhibit superior lithium storage performance.