Mixed transition metal oxide nanowire arrays enabling hybrid capacitor performance enhancement

Abstract

Electrode materials with excellent electrochemical performance are very significant for energy storage devices. However, single structured electrode materials present poor conductivity and cycling stability. In this work, we prepare MnO₂@NiCo₂O₄ nanowire arrays by a simple hydrothermal method. The as-fabricated product exhibits a specific capacitance of 452.1 C g⁻¹ at 10 A g⁻¹. The assembled device keeps 82.1% capacitance retention after 10 000 cycles and delivers an energy density of 31.8 W h kg⁻¹ at a power density of 2241.6 W kg⁻¹. This superior electrochemical performance can be ascribed to the unique spatial structure, demonstrating potential application in next generation micro/nanodevices.