Flexible, large-area, all-solid-state supercapacitors using spray deposited PEDOT:PSS/reduced-graphene oxide

Textile-based, flexible, all-solid-state supercapacitors are in high demand for short-term power backup and future wearable applications. Here we report a one-step spray technique to fabricate large-area flexible electrodes using poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS), reduced graphene oxide (rGO), and carbon cloth (CC). H₃PO₄-treated CC/PEDOT:PSS and CC/PEDOT:PSS-rGO electrodes exhibit enhanced capacitance, high rate capability, and a wide voltage window (0–2.0 V). The CC/PEDOT:PSS and CC/PEDOT:PSS-rGO(20 wt%) electrodes exhibit respective specific capacitances of ∼73 and ∼170 F g⁻¹ at 10 mV s⁻¹, with energy and power densities of 2.6 Wh kg⁻¹ and 2880 W kg⁻¹ and of 11.0 Wh kg⁻¹ and 4460 W kg⁻¹, respectively. The device with a 25.0 cm² active area display capacitances of ∼6.5 and ∼5.5 F per electrode at mass loadings of 4.0 and 2.4 mg cm⁻², respectively. The CC/PEDOT:PSS-rGO devices have excellent cyclic and bending stability, with capacitance retention of ∼100% after 2000 cycles and of ∼95% under bending of radius 0.5 mm. A fully charged compound device of three devices connected in series is able to power white and green LEDs.