RESUMEN
In this study, flexible and low-cost graphite sheets modified by atmospheric pressure plasma jet are applied to reduced-graphene-oxide/polyaniline supercapacitors. Surface treatment by atmospheric pressure plasma jet can make the hydrophobic surface of graphite into a hydrophilic surface and improve the adhesion of the screen-printed reduced-graphene-oxide/polyaniline on the graphite sheets. After the fabrication of reduced-graphene-oxide/polyaniline supercapacitors with polyvinyl alcohol/H2SO4 gel electrolyte, pseudo-capacitance and electrical double capacitance can be clearly identified by the measurement of cyclic voltammetry. The fabricated supercapacitor exhibits specific capacitance value of 227.32 F/g and areal capacitance value of 28.37 mF/cm2 with a potential scan rate of 2 mV/s. Meanwhile, the capacitance retention rate can reach 86.9% after 1000-cycle cyclic voltammetry test. A light-emitting diode can be lit by the fabricated reduced-graphene-oxide/polyaniline supercapacitors, which confirms that the supercapacitors function well and can potentially be used in a circuit.
RESUMEN
This study evaluates DC-pulse nitrogen atmospheric-pressure-plasma-jet processed carbon nanotube (CNT)-reduced graphene oxide (rGO) nanocomposites for gel-electrolyte supercapacitor applications. X-ray photoelectron spectroscopy (XPS) indicates decreased oxygen content (mainly, C-O bonding content) after nitrogen APPJ processing owing to the oxidation and vaporization of ethyl cellulose. Nitrogen APPJ processing introduces nitrogen doping and improves the hydrophilicity of the CNT-rGO nanocomposites. Raman analysis indicates that nitrogen APPJ processing introduces defects and/or surface functional groups on the nanocomposites. The processed CNT-rGO nanocomposites on carbon cloth are applied to the electrodes of H2SO4-polyvinyl alcohol (PVA) gel-electrolyte supercapacitors. The best achieved specific (areal) capacitance is 93.1 F g-1 (9.1 mF cm-2) with 15 s APPJ-processed CNT-rGO nanocomposite electrodes, as evaluated by cyclic voltammetry under a potential scan rate of 2 mV s-1. The addition of rGOs in CNTs in the nanoporous electrodes improves the supercapacitor performance.