Rational design of NiCo2S4 nanoparticles @ N-doped CNT for hybrid supercapacitor

A simple hydrothermal route is designed to decorate NiCo2S4 nanoparticles on the surface of N-doped carbon nanotubes to form a coaxial composite (NiCo2S4@NCNT). Inherited the high electrical conductivity from the NCNT and high capacitive performance of NiCo2S4, the optimized NiCo2S4@NCNT composite could significantly reduce the contact resistance and effectively increase the transfer rate of ion and electron and thus benefit for its electrochemical performance enhancement. When employed as a battery-type supercapacitor electrode, the NiCo2S4@NCNT composite exhibits a high capacitance up to 783.5 C g−1 at 1 A g−1 and as well as rate performance (74.6% retention with the current density increases from 1 to 50 A g−1). Coupled with activated carbon (AC) negative electrode, the as-assembled hydride supercapacitor delivers a maximum energy density of 49.75 Wh kg−1 at a power density of 774.65 W kg−1, as well as 88.9% capacitance retained after 3000 cycles at a current density of 10 A g−1. These above results demonstrate the enormous potential of NiCo2S4@NCNT in the development of hybrid supercapacitors.