WS2 nanoflowers on carbon nanotube vines with enhanced electrochemical performances for lithium and sodium-ion batteries

Abstract

Hybrids of tungsten disulfide (WS2, 74.7%) nanoflowers on multi–walled carbon nanotube veins have been produced and characterized. The petal–like WS2 nanosheets with diameters of 307 ± 52 nm are in situ grown on the carbon nanotubes to obtain the hybrid structure resembling to flowers (WS2 nanosheets) on vines (carbon nanotubes with diameters of 10 ± 3 nm), where the carbon nanotube vines are wrapped by WS2 petals through core–shell growth, resulting in a strong interface connection. The electrochemical performances of the hybrids have been significantly enhanced, especially at high current densities, since the charges can be effective transported from WS2 to carbon nanotube conductive networks. The specific capacities of the hybrids are more than three times (seven times) of those of pristine WS2 and MWCNTs as anodes for lithium ion batteries (sodium ion batteries) at current rates of 2–3 A g−1. The cycling capacities of WS2–MWCNTs at a current rate of 1 A g−1 are comparable or higher than those reported for WS2 composites at current rates of 100 or 200 mA g−1.