title: Sulfur encapsulated in a TiO2-anchored hollow carbon nanofiber hybrid nanostructure for lithium-sulfur batteries.
abstract: A hollow carbon nanofiber hybrid nanostructure anchored with titanium dioxide (HCNF@TiO2) was prepared as a matrix for effective trapping of sulfur and polysulfides as a cathode material for Li-S batteries. The synthesized composites were characterized and examined by X-ray diffraction, nitrogen adsorption-desorption measurements, field-emission scanning electron microscopy, scanning transmission electron microscopy, and electrochemical methods such as galvanostatic charge/discharge, rate performance, and electrochemical impedance spectroscopy tests. The obtained HCNF@TiO2-S composite showed a clear core-shell structure with TiO2 nanoparticles coating the surface of the HCNF and sulfur homogeneously distributed in the coating layer. The HCNF@TiO2-S composite exhibited much better electrochemical performance than the HCNF-S composite, which delivered an initial discharge capacity of 1040 mA h g(-1) and maintained 650 mAh g(-1) after 200 cycles at a 0.5 C rate. The improvements of electrochemical performances might be attributed to the unique hybrid nanostructure of HCNF@TiO2 and good dispersion of sulfur in the HCNF@TiO2-S composite.
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha 410083 (P.R. China), Fax: (+86) 731-88830649. zza75@163.com.
authors.forename: Zhian
authors.initials: Z
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Shaofeng
authors.initials: S
authors.lastname: Jiang
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Lai
authors.forename: Jie
authors.initials: J
authors.lastname: Li
keywords: cathodes; electrochemistry; hollow carbon nanofibers; hybrid nanostructures; lithium-sulfur batteries; titanium dioxide