Rational design of porous NiCo2S4 nanotubes for hybrid supercapacitor

The nanotube-consisted flower-like NiCo2S4 is successfully fabricated by a novel two-step hydrothermal technique. X-ray diffraction (XRD) identifies the spinel structure, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imply the flower-like morphology of the synthesized NiCo2S4. The electrochemical behaviors are studied by cyclic voltammetry and galvanostatic charge-discharge measurements. The NiCo2S4 nanotubes demonstrate enhanced pseudocapacitive performance of 429.5 C g(-1) at current density of 0.5 A g(-1). The NiCo2S4//AC device delivers high energy density of 37.69 Wh kg(-1), maximum power density of 4000.6 W kg(-1) and satisfied cycle property of 96% capacitance retention after over 7000 cycles. The results show that the NiCo2S4 nanotubes are promising electrode material for high performance supercapacitor applications.