Effect of Interleaved Electrolyte Forms on Macro-scaled Structural Hybrid Supercapacitors with Asymmetric Configurations of Graphene-coated Carbon Fabric Electrodes

Structural composites supercapacitors are manufactured by converting commercial carbon fabrics into electrodes by applying a surface treatment without changing their sizing chemistry, integrating electrolytes with single and hybrid material components in the forms of solution, gel, and film, with glass fabrics as a separator to prevent short-circuit in the system. Carbon fabrics are treated by applying stepwise dip-coating method including graphene oxide (GO) coating, FeO treatment and reduction steps in aqueous medium. Four configured supercapacitors are tested by changing electrodes and electrolytes. Supercapacitor with reduced GO (rGO) and rGO-FeO coated carbon fabric electrodes with mesoporous PVA-KOH film electrolyte in the laminated structure covered by insulator films demonstrates 46% charge retention at 1 V after 30 s, 21 Ω charge transfer resistance, 120 mWh/kg energy density, 3.12 W/kg power density, and 0.35 mF/g specific capacitance. Electrolytes in gel and solution forms do not display any capacitance behavior in cyclic voltammetry analysis and exhibit lower energy densities compared to the film electrolyte. PVA-KOH film electrolyte provides a synergistic effect with resized commercial grade carbon fabric electrodes through its homogenous impregnation on electrode surfaces which is responsible for the enhancement of charge-storage behavior of the fabricated structural supercapacitors.