Highly Flexible and Self-Healable Zinc-Ion Hybrid Supercapacitors Based on MWCNTs-RGO Fibers

As the flexible wearable devices are developing rapidly, the requirement for energy storage devices with high energy and power density, excellent flexibility, and high reliability is increasing. Fiber-shaped supercapacitors offering high power density and excellent flexibility have attracted widespread attention. However, the low energy density and poor reliability limit the practical application of these fiber-shaped supercapacitors. To overcome these problems, a new zinc-ion hybrid fiber supercapacitor (ZHFSC) is designed and realized. As both capacitor-type and battery-type energy storage mechanisms can be used, the energy density of ZHFSC is expected to be improved. Furthermore, the excellent self-healability of poly(vinyl alcohol) (PVA)/Zn(CF3SO3)(2)aqueous gel electrolyte contributes to the high reliability of the ZHFSC. As a proof of concept, the maximum power density and energy density of the ZHFSC are, respectively, as high as 1433.2 mW cm(-3)and 13.1 mWh cm(-3), and the capacitance retention, respectively, has the high values of 87.8% and 70.5% under the bending degree of 150 degrees and after the fifth self-healing. This study offers an efficient method to realize the high-performance supercapacitors for flexible wearable devices in the future.