High-performance quasi-solid-state flexible supercapacitors based on a flower-like NiCo metal-organic framework.

NiCo metal-organic framework (MOF) electrodes were prepared by a simple hydrothermal method. The flower-like NiCo MOF electrode exhibited an exciting potential window of 1.2 V and an excellent specific capacitance of 927.1 F g -1 at 1 A g -1 . The flower-like NiCo MOF//activated carbon (AC) device delivered a high energy density of 28.5 W hkg -1 at a power density of 400.5 W kg -1 and good cycle stability (95.4% after 5000 cycles at 10 A g -1 ). Based on the flower-like NiCo MOF electrode, the asymmetric quasi-solid-state flexible supercapacitor (AFSC) was prepared and exhibited good capacitance retention after bending (79% after 100 bends and 64.4% after 200 bends). Furthermore, two AFSCs in series successfully lit up ten parallel red LED lights, showing great application potential in flexible and wearable energy storage devices.