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Lithium-sulfur batteries have received lots of attention due to their high energy density and cheap material. The poor electrical conductivity and slow electrochemical kinetics of sulfur hinder their application. Here, we in situ grow Ni12P5 on carbon nanotube to prepare composites as sulfur host. Electrochemical tests show that Ni12P5 acts as an electrocatalyst in the lithium-sulfur batteries, initiating the oxidation of Li2S6 and Li2S4 at higher potentials, significantly improving the reaction kinetics during charging and discharging. The CNT@Ni12P5/S composite exhibited 1352 mAh/g initial discharge capacity at 0.1 C and a retention capacity of 85% after 100 cycles at 0.2 C. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries received intense attention because of their high-energy density and inexpensive active material. However, the poor electrical conductivity of sulfur, shuttle effect, and slow electrochemical kinetics hinder their application. Herein, cobalt disulfides uniformly in situ grow on the surface of carbon nanotubes to prepare a three-dimensional carbon nanotubes-cobalt disulfide composite material as the sulfur host. The in situ growth cobalt disulfides on the carbon nanotube is confirmed to play the role of electrocatalyst, triggering the oxidation reaction of Li2S6 and Li2S4 at a higher potential, which promotes the conversion of Li2S6 to Li2S4 and Li2S4 to Li2S2, respectively, and significantly enhances the electrochemical reaction kinetics during the charge and discharge process. Particularly, the carbon nanotubes-cobalt disulfide-20 composite provides a suitable number of active sites for Li2S6 and Li2S4 and exerts an initial discharge capacity of 1253 mA h g−1 at 0.1 C and a retentive capacity of 84% after 200 cycles at 0.2 C. [ABSTRACT FROM AUTHOR]