In this study, a hierarchical ZnCo2O4@MnO2 core–shell nanotube arrays electrode was developed by a facile two-step method.

Miniaturized energy storage devices have attracted considerable research attention due to their promising applications in various smart electronic devices.

In this paper, we report CoNi 2 S 4 nanowire arrays (NWAs) on 3D nickel foams based on an anion-exchange reaction which involved the pseudo Kirkendall effect. Due to the low electronegativity of sulfur, CoNi 2 S 4 NWAs exhibit higher conductivity compared with Ni-Co oxide NWAs when used as active materials in supercapacitors. The electrochemistry tests show that these self-supported electrodes are able to deliver ultrahigh specific capacitance (1250 F g À1 at a current density of 5 mA cm À2 ), together with a considerable areal capacitance (2.5 F cm À2 at a current density of 5 mA cm À2 ), Furthermore, a capacitance retention of 72% after 5000 charge-discharge cycles at 5 mA cm À2 is obtained, indicating the excellent cycling stability of the CoNi 2 S 4 NWA/nickel foam electrode. The superior electrochemistry capacity demonstrates that CoNi 2 S 4 NWAs are promising electrode materials for supercapacitor applications.Scheme 1 Schematic illustration of the fabrication process for Ni-Co sulfide nanowire arrays.This journal is