ZnCo2O4 nanowire arrays grown on nickel foam for high-performance pseudocapacitors

Abstract

Uniform ZnCo₂O₄ nanowire arrays were directly grown on nickel foam through a facile hydrothermal method and subsequent thermal treatment process. The ZnCo₂O₄ nanowires have diameters of about 100 nm and lengths of up to 5 μm. The as-obtained ZnCo₂O₄ nanowire array loaded nickel foam can be directly applied as an electrode for high-performance supercapacitors. Electrochemical measurements show that the ZnCo₂O₄/nickel foam electrode has high specific capacitance (1625 F g⁻¹ at 5 A g⁻¹), excellent rate capability (59% capacitance retention at 80 A g⁻¹) and good cycling stability (94% capacitance retention over 5000 charge–discharge cycles). This work demonstrates that ZnCo₂O₄ nanowires are highly desirable for application as advanced electrochemical electrode materials.