NiCo2O4 nanosheet stereostructure with N-doped carbon/Co array supports derived from Co-MOF for asymmetric supercapacitor

The performance of supercapacitors not only depends on the structure of the electrode but also relates to the composition of electrode material. The binder-free integrated electrodes were obtained from NiCo2O4 nanosheets grown on nitrogen-doped carbon and Co aggregation (NC/Co) nanowires through a hydrothermal process and subsequent annealing. The NiCo2O4@NC/Co composite presents the stereostructure with NC/Co nanowire supports and intertwined NiCo2O4 ultrathin nanosheets. The NiCo2O4@NC/Co electrode demon-strates excellent electrochemical capacitive performances and cycling stability, where it illustrates a splendid specific capacitance of 1112 F g-1 at 1 A g-1 and maintains around 90.7 % of the maximum capacitance after 5000 cycles. Besides, the functionalized asymmetric supercapacitor (ASC) was fabricated based on NiCo2O4@NC/Co and NC with KOH-PVA solid electrolyte. The NiCo2O4@NC/Co // NC ASC possesses a stabi-lized operating potential range of 1.6 V and retains around 81.1 % retention after 5000 cycles. This makes a great potential for Ni-Co multiple compound electrodes for high-performance energy storage systems.