One-step magneto-solvothermal synthesis of porous network NiCo2S4 for high-performance supercapacitors

Abstract

A simple one-step magneto-solvothermal method is developed to prepare three-dimensional porous network nickel cobalt sulfide (NiCo2S4) as electrodes for supercapacitors, resulting in excellent electrochemical performance. By taking advantage of the modulation of the microscopic morphology by the magnetic fields, NiCo2S4 electrodes exhibit high specific capacitance (605.8 C/g at 1 A/g) and excellent rate capability (80% remained capacitance after 3000 charge–discharge cycles at a current density of 10 A/g) because of significant increase in the exposure of the active sites. Moreover, hybrid supercapacitors fabricated by NiCo2S4 prepared under a magnetic field of 3 T as the positive electrode and carbon electrode (activated carbon) as the negative electrode demonstrate a high energy density of 22.65 Wh/kg at the power density of 750.14 W/kg and excellent cycling stability. This work provides a novel route to improve the electrochemical performances of NiCo2S4 using magneto-solvothermal method.