Confine Sulfur in Polyaniline-Decorated Hollow Carbon Nanofiber Hybrid Nanostructure for Lithium-Sulfur Batteries

A polyaniline-decorated hollow carbon nanofiber (HCNF@PANI) hybrid nanostructure was prepared as a conductive 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, Fourier transformation infrared spectroscopy, nitrogen adsorption-desorption measurements, field emission scanning electron microscopy, scanning transmission electron microscopy, and electrochemical methods, such as cyclic voltammetry, galvanostatic charge-discharge tests, and rate performance tests. The obtained HCNF@PANI-S composite showed an obvious core-shell structure with a PANI layer coating on the surface of the HCNF, and sulfur homogeneously distributes in the coating layer. The HCNF@PANI-S composite exhibited much better electrochemical performance than the HCNF-S composite, which delivered initial discharge capacity of 960 mAh g(-1) maintained 535 mA g(-1) after 200 cycles at 0.5 C rate. The improvements of electrochemical performances may be attributed to the unique hybrid nanostructure of HCNF@PANI and good dispersion of sulfur in the HCNF@PANI-S composite.