Electrophoretic deposition of RuO2/HRGO composites for flexible supercapacitor electrodes

Flexible energy storage devices are essential for the development of wearable electronics, such as bendable displays and wearable multi-media systems. A subset of these energy storage devices, flexible supercapacitors have received increased attention because of their long cycle life, low cost, and easy fabrication. Herein, we report an easy and low cost method to fabricate bendable ruthenium oxide (RuO$_{\mathrm{2}})$/ holey reduced graphene oxide (HRGO) electrodes using electrophoretic deposition. Analysis of the surface morphology using scanning electron microscopy (SEM) shows a highly nanoporous structure with pores ranging from 2 to 3 nm. The obtained RuO$_{\mathrm{2}}$/HRGO supercapacitor exhibited excellent electrochemical capacitive performance in a PVA-H$_{\mathrm{2}}$SO$_{\mathrm{4}}$ gel electrolyte, with a specific capacitance of 418.5F/g. Additionally, a high rate performance with capacitance retention of 85{\%} was observed when the current was increased by a factor of 20 from 1.0 to 20.0 A/g. The supercapacitor exhibited an exceptional cycling stability of 88.5{\%} after 10,000 cycles, indicating excellent long term electrochemical stability.