All-in-one flexible asymmetric supercapacitor based on composite of polypyrrole-graphene oxide and poly(3,4-ethylenedioxythiophene)

The rapid development of personal electronic equipment has stimulated the research upsurge on flexible supercapacitors with high energy density and bending tolerance. Construction of flexible asymmetric supercapacitors can effectively improve the energy density via broadening voltage window. Up to date, most of the asymmetric devices are fabricated by assembling anode, cathode and separator together, which inevitably brings unnecessary mass and volume, and makes the components poorly contacted, and decreases the resistance to repeated bending of devices. To overcome these issues, we design an integrated flexible asymmetric supercapacitor. Continuous gold layers are deposited on the two sides of the porous organic film to form the Au/porous film/Au sandwich structure, and poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole-graphene oxide (PPy-GO) are then electrochemically deposited on two gold layers respectively to serve as the positive and negative electrode material. As expected, the obtained devices expand the operating voltage to 1.2 V when Li2SO4/polyvinylene alcohol is used as gel electrolyte. The optimal cell possesses energy density of 2.98 mu Wh cm(-2) at 0.12 mW cm(-2), exhibits excellent bending tolerance (capacitance can retain 99.3% of its initial value after 10000 repeated bending cycles). Meanwhile, the devices can be connected in series by simple super-position and light up a light-emitting diode. This flexible integrated device may exhibit potential applications in the future. (C) 2020 Elsevier B.V. All rights reserved.