Rational synthesis of hybrid NiCo2S4@MnO2 heterostructures for supercapacitor electrodes

Abstract In this work, unique NiCo 2 S 4 @MnO 2 heterostructures have been successfully synthesized by a mild hydrothermal method, and applied as supercapacitor electrodes. The NiCo 2 S 4 @MnO 2 electrode has a high specific capacitance (520.7 F g −1 at a current density of 1 A g −1 ), and perfect rate performance (78.6% capacitance retention from 1 A g −1 to 10 A g −1 ), as well as good cycling performance (86.8% retention after 2000 cycles) in a three-electrode system. Such unique nanostructures and their high specific area are beneficial to provide sufficient active sites for effective redox reaction and enhance capacitive performances. In principle, these findings manifest that the unique NiCo 2 S 4 @MnO 2 nanocomposites are promising for energy storage application.