An electropolymerized
poly(3,4-ethylenedioxythiophene) (PEDOT)/screen-printed
reduced graphene oxide (rGO)–chitosan (CS) bilayer material
was coated on carbon cloth to form electrodes for gel-electrolyte
flexible supercapacitors. The conductive polymer and carbon-based
materials mainly contribute pseudocapacitance (PC) and electrical
double-layer capacitance (EDLC), respectively. The high porosity and
hydrophilicity of the PEDOT/rGO–CS bilayer material offers
a large contact area and improves the contact quality for the gel
electrolyte, thereby enhancing the capacitive performance. Cyclic
voltammetry (CV) under a potential scan rate of 2 mV/s revealed that
a maximum areal capacitance of 1073.67 mF/cm2 was achieved.
The capacitance contribution ratio PC/EDLC was evaluated to be ∼67/33
by the Trasatti method. A 10,000-cycle CV test showed a capacitance
retention rate of 99.3% under a potential scan rate of 200 mV/s, indicating
good stability. The areal capacitance remains similar under bending
with a bending curvature of up to 1.5 cm–1.