CuO Nanoflowers growing on Carbon Fiber Fabric for Flexible High-Performance Supercapacitors

Graphical abstract: One of the best electrochemical performances for CuOelectrodes based supercapacitorisachieved by the CuOhierarchical structure growing on the carbon fiber fabric (CuO/CFF) in aqueous electrolyte. Meanwhile, a flexible solid-state supercapacitoris also fabricated as a promising candidate in energy storage for flexible, wearable and lightweight electronics. - Highlights: • The electrodes are fabricated by cupric oxide growing on carbon fiber fabric (CuO/CFF). • The capacitor performance is optimized by the mass loading. • One of the best electrochemical performances is achieved for CuO/CFF supercapacitor. • A highly flexible solid-state supercapacitor can power 3 light-emitting diodes for about 5 min. - Abstract: A hierarchical CuO nano-structure is prepared by directly growing CuO nanoflowers on carbon fiber fabric (CuO/CFF) via a hydrothermal method. The CuO/CFF is used as the electrode material of a supercapacitor for electrochemical energy storage. The supercapacitor displays superior electrochemical performance in aqueous electrolyte with the specific capacitance of 839.9 F/g at the scan rate of 1 mV/s, energy density of 10.05 Wh/kg and power density of 1798.5 W/kg, which are the highest values for the CuO/CFF electrodes. Moreover, a flexible symmetric solid-state symmetric supercapacitor is also fabricated by using the CuO/CFF as electrodes. The solid-state supercapacitor exhibits a specific capacitance of 131.34 F/g at the scan rate of 1 mV/s with a power density of 145.12 W/kg, and 95.8% capacitance retention after 2000 charge-discharge cycles.