Binder-free hierarchical core-shell-like CoMn2O4@MnS nanowire arrays on nickel foam as a battery-type electrode material for high-performance supercapacitors

Abstract Binder-free hierarchical core-shell-like CoMn2O4@MnS heterostructures have been successfully grown on the surface of nickel (Ni) foam using facile two-step hydrothermal deposition route. In supercapacitor applications, the as-prepared core-shell-like CoMn2O4@MnS composite electrode has been used successfully as a battery-type material. Scanning electron microscope (SEM) and transmission electron microscope characterizations reveal that the as-prepared CoMn2O4@MnS electrode delivers a dandelion-like heterostructures that contains the MnS nanoparticles grown on the surface of CoMn2O4 nanowire arrays (NWAs), resulting a core-shell-like structure. In addition to increasing electrochemical behaviour and precise surface area, the novel core-shell-like heterostructures provide superhighways for the ultra-fast transfer of electrons and ions. The probable plateaus of cyclic voltammetry and galvanostatic charge-discharge experiments suggest that Faradic battery-type redox activity is given by the as-prepared core-shell-like CoMn2O4@MnS NWAs electrode. As a battery-type material, core-shell-like CoMn2O4@MnS NWAs electrode exhibits a outstanding specific capacity of (~213.0 mA h g−1 at 2 Ag−1), remarkable rate capability (~89.91% retains even at 10 A g−1), and excellent cycling stability (~91.42% at 6 A g−1 over 5000 cycles), which are much higher than those of the bare CoMn2O4 electrode. The excellent energy storage performance corroborates that CoMn2O4@MnS NWAs can serve as an advanced battery-type electrode material for supercapacitor applications.