Abstract
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Stretchable reduced graphene oxide (rGO)/single-wall carbon nanotubes (SWNTs) composite electrodes were prepared using a spray coating technique onto gold-coated latex substrates. Poly(vinyl alcohol) (PVA)/phosphoric acid (H
3 PO4 ) was used as a stretchable electrolyte in order to assemble a symmetrical electrochemical capacitor (EC). Cyclic voltammetry (CV) indicated a typical double layer capacitance, even after a number of stretching cycles. Electrochemical impedance spectroscopy (EIS) showed a well-defined capacitive responsewith lowinternal resistance after repetitive stretching to 100% strain.Galvanostatic charge/discharge measurements with up to 100 stretch cycles yielded symmetrical charge/discharge curves indicating reversibility and facile kinetics. The highest capacitance of an unstrained latex EC was 61 F g-1 (15.3 mF cm-2), which decreased to 49 F g-1 (12.3 mF cm-2) and 42 F g-1 (10.5 mF cm-2) after 50 and 100 stretching cycles, respectively. The stretchable EC subjected to 100 stretching cycles retained approximately 67% of its initial capacitance value after 3,000 charge/discharge cycles.