Electrochemical performance enhancement of high mass loading H-RuO2NPs electrode and aqueous symmetrical supercapacitor in the neutral electrolyte

Abstract

Abstract In this work, high water content hydrous ruthenium oxide nanoparticles (H-RuO2NPs) were synthesized using gallic acid monohydrate as a reducing agent. X-ray diffraction and transmission electron microscopy results confirmed the formation of irregular shape H-RuO2NPs with an average size of 5 nm. The thermogravimetric study showed that the synthesized H-RuO2NPs content more than 70 % of water which makes it specifically suitable for the electrochemical application. Moreover, it was observed that increasing the mass loading of synthesized H-RuO2NPs from 0.5 mg cm−2 to 8 mg cm−2, the specific capacitance decreased from 676 to 217 Fg −1 at a scan rate of 5 mVs−1 in 1 M Na2SO4 electrolyte. Furthermore, the aqueous symmetrical supercapacitor with a total mass loading of 16 mg cm−2 exhibited a specific capacitance of 62 Fg −1 at a scan rate of 1 mVs−1 and the specific capacitance retention rate of 91.4 % was observed after 5000 cycles at a current density of 5 Ag−1.