Enhancing the specific capacitance of SrRuO3 and reduced graphene oxide in NaNO3, H3PO4 and KOH electrolytes

• Published in: Electrochimica acta Vol. 260; pp. 738 - 747
• Main Authors: Galal, Ahmed, Hassan, Hagar K., Jacob, Timo, Atta, Nada F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.01.2018
• Subjects: Effect of electrolyte; Nano-SrRuO3; Perovskites; Reduced graphene oxides; Supercapacitors; Supercapacitors; Perovskites; Nano-SrRuO3; Effect of electrolyte; Reduced graphene oxides
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.12.026

The specific capacitance (Cs), cycling stability, energy and power densities of SrRuO3 (SRO) have been enhanced by reduced graphene oxide (RGO) in the form of SrRuO3-RGO (SRGO) composites. The high conductivity as well as the large specific surface area of RGO result in an improvement of the electrochemical and capacitive properties of SRO. The combination between RGO and SRO helps minimizing the mass percentage of Ru to 20.4% compared to 60% in RuO2 and 43% in the individual SRO of commercial Ru-based supercapacitors. The electrochemical properties of RGO, SRO and SRGO were studied in three different electrolytes (1.0 M NaNO3, 1.0 M H3PO4 and 1.0 M KOH), in which these materials are known to possess their optimum capacitances. We have found that RGO improves the Cs of SRO: from 13.8 F g−1 to 62.4 F g−1 in 1.0 M NaNO3, from 24.5 F g−1 to 101 F g−1 in 1.0 M H3PO4 and from 52.4 F g−1 to 160 F g−1 in 1.0 M KOH, respectively. Moreover, it improves the cycling stability of SRO in all the studied electrolytes. In this study, we have found that 1.0 M H3PO4 is suitable for high energy density applications, while KOH results in a supercapacitor of high maximum power density. [Display omitted] •SrRuO3-RGO nanostructured composite was synthesized by a simple method.•The composite was used effectively as supercapacitor in neutral, basic and acid media.•Ru-loading was reduced to 20% in SrRuO3 compared to 60% in RuO2-based capacitors.•Cs values are 62.4 F g−1, 101 F g−1 and 160 F g−1 in NaNO3, H3PO4 and KOH, respectively.