▎ 摘　　要

In this work, we studied the effect of adding a redox electrolyte on the specific capacitance of SrRuO3-reduced graphene oxide (SRGO) nanocomposite electrode. Two redox systems were considered, quinone/hydroquinone and triiodide/iodide (I-3(-)/I-) in acidic (H3PO4) and neutral (NaNO3) solutions. The employment of reduced graphene oxide reduces the amount of Ru loading to the surface down to 20% to achieve a specific capacitance (C-s) of 62.4 F.g(-1) in 1.0 M NaNO3 and 101 F.g(-1) in 1.0 M H3PO4. The C-s of the electrode increased by 21.6 folds in KI-containing NaNO3 solutions compared with the NaNO3 electrolyte. The presence of the redox system in the electrolyte enhanced the cycling stability of the electrode to 173% compared with its initial value after 1000 galvanic charging/discharging (GCD) cycles compared with 93% in its absence. The presence of redox-intermediates including iodine (I-2) participate in the surface reaction and contribute to the observed enhancement in both C-s and cycling GCD. A maximum C-s value of 1037 F.g(-1) (733 mF.cm(-2)) at 5 A.g(-1) was obtained by using SRGO/0.08 M KI-1.0 M NaNO3.