NiCo2S4 nanoparticles embedded in nitrogen-doped carbon nanotubes networks as effective sulfur carriers for advanced Lithium–Sulfur batteries

Abstract To enhance the electrochemical performance of Li–S battery, a composite sulfur cathode was designed by doping sulfur onto N-doped carbon nanotubes with metal sulfide particles attached to their surface. This designing approach allowed performing high sulfur loading in the cathode, while maintaining prominent stability and good charge/discharge capacity. The results showed that at a sulfur loading of 2.1 mg cm−2, the cell with S/NiCo2S4/N-CNT cathode delivered an average discharge capacity of 998 mA h g−1 at 0.1C, and preserved an excellent discharge capacity of 713 mA h g−1 at a high current density of 1 C. At the same time, the cell demonstrated high stability and reversibility delivering a capacity of 950 mA h g-l when current density reduced back again to 0.1C. Furthermore, the S/NiCo2S4/N-CNT cathode showed a steady capacity of 915 mA h g−1 at 0.2C over 100 cycles.