Facile Method of Fabricating Interdigitated and Sandwich Electrodes for High-Performance and Flexible Reduced Graphene Oxide@Polyaniline Nanocomposite Supercapacitors

Flexible supercapacitors (SCs), with a guideline of future perspective as one of the emerging energy storage devices, are facing key challenges for producing imminent portable and bendable electronic devices. Some of these challenges are the rational architecture of supercapacitors and the preparation of high-performance active materials. Herein, we used a simple, environmentally degradable, and scalable approach for the design and fabrication of interdigitated and sandwich electrodes. The active material of planar and sandwich-type supercapacitors and reduced graphene oxide@polyaniline nanocomposites were prepared by the hydrothermal method and directly drop-cast on the poly(ethylene terephthalate) (PET) substrate as supercapacitor electrodes. In this method, although we did not use mechanical press, active materials possess excellent adhesion to the substrate. The capacitance of our prepared planar supercapacitor was 99 F/g at a 0.5 mA current and demonstrated good stability after 1000 cycles at a 5 A/g current density; the capacitance retention rates remained over 98.3%. Our prepared sandwich-type supercapacitors showed a low charge transfer resistance (Rct = 1.75 Ω) and achieved a capacitance retention of 83% when the current density changed from 0.25 to 5.0 A/g. These reveal their promising potential for high-performance supercapacitor applications in future electronic productions.