Construction of a nanostructured NiCo2S4/Ni/Ni9S8 composite for energy storage applications
Abstract
It is necessary to investigate and develop nickel-cobalt sulfide electrodes with superior electrochemical behavior. This work produced the NiCo2S4/Ni/Ni9S8 nanostructure composite (NCS/N/NS) for energy storage in supercapacitors using a solvothermal technique with polyethyleneimine (PEI) as a carbon source, followed by an hour of annealing in an argon atmosphere, and a hydrothermal method with thiourea as a sulfur and nitrogen source. Outstanding electrochemical energy storage properties are provided by NCS/N/NS. The produced electrode material, NCS/N/NS, demonstrated an exceptional capacitance of 1620 F g-1 (696 C g-1) at 1 A g-1 when employed for SCs. An NCS/N/NS was used as the positively charged electrode and the opposite electrode of commercial AC to build an NCS/N/NS//activated carbon (AC) asymmetric device for practical usage. At 1 A g-1, the asymmetric device produced a specific power of 887 W kg-1 and a unique specific energy of 53 Wh kg-1. Moreover, it exhibits a 100% coulombic efficacy and a 95% capacity retention after 3000 cycles, respectively.
