Assembly of NiO/Ni(OH)2/PEDOT nanocomposites on contra wires for fiber-shaped flexible asymmetric supercapacitors

Fiber-shaped solid-state supercapacitors have aroused much interest in the fields of portable devices because of their attractive features such as high flexibility and safety, tiny volume, and high power density. In this work, NiO/Ni(OH)2 nanoflowers encapsulated in three-dimensional interconnected poly(3,4-ethylenedioxythiophene) (PEDOT) have been fabricated on contra wires through a mild electrochemical route. The as-formed hybrid electrode made of NiO/Ni(OH)2/PEDOT delivered a high specific capacitance of 404.1 mF cm−2 (or 80.8 F cm−3) at a current density of 4 mA cm−2 and a long cycle life with 82.2% capacitance retention after 1000 cycles. Furthermore, a fiber-shaped flexible all-solid-state asymmetric supercapacitor based on the resulting hybrid electrode was assembled. The energy density of 0.011 mWh cm−2 at a power density of 0.33 mW cm−2 was achieved under an operating voltage window of 1.45 V. This work provides an effective strategy to fabricate high-performance electrodes for fiber-shaped flexible asymmetric supercapacitors through a facile and low-cost route