Ternary ZnCo2O4 Nanowire Electrode Materials for High-Capacitance and Flexible Electrochemical Capacitors

Spinel-structured oxides are promising candidates for supercapacitor electrodes owing to their features of low price and environmental friendliness. However, their large-scale applications are restricted in view of their low energy density and electrical conductivity. In this work, we synthesize wire-like ZnCo2O4 nanomaterials by a facile hydrothermal avenue and a subsequent calcination process. The prepared samples possess a large specific surface area, which is beneficial for increasing active sites and shortening the ion diffusion channels. The as-assembled asymmetric supercapacitor delivers an energy density of 64 Wh kg–1 at 2880 W kg–1. And the capacitance can be maintained at 85% after 10,000 cycles at the current density of 2 A g–1. The device indicates excellent mechanical stability when bending various angles, revealing its potential application in portable energy storage devices.