Electrochemical performance of flexible poly(ethylene terephthalate) (PET) supercapacitor based on reduced graphene oxide (rGO)/single-wall carbon nanotubes (SWNTs)

• Flexible supercapacitor was fabricated using reduced graphene oxide (rGO)/single-walled carbon nanotubes (SWNTs)/PET substrate.
• Flexible rGO/SWNTs/PET supercapacitor showed 75% retention of initial capacitance at 30° bending condition.
• Supercapacitor was maintained 72% of its initial capacitance value after 3000 charge/discharge cycles under 30° bending condition.
• It showed 75% of initial capacitance after 500 bending with application of 6000 charge/discharge cycles.

The reduced graphene oxide (rGO)/single-wall carbon nanotubes (SWNTs) composites are deposited onto the poly(ethylene terephthalate) (PET) substrate using spray coating technique to fabricate a flexible supercapacitor. The electrochemical properties of the PET complete device as a function of bending cycles and angles are performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge tests. The EIS and charge/discharge curves of the flexible PET supercapacitor show good capacitive behavior even after prolonged bending cycles up to 500. The highest capacitance value obtains for the unbent PET supercapacitor is 42.2 F g−1 (8.8 mF cm−2). The capacitance value of the PET supercapacitor is retained 75% after 500 bending with 6000th galvanostatic charge/discharge cycles.