Enhanced electrochemical performance of nickel-cobalt-oxide@reduced graphene oxide//activated carbon asymmetric supercapacitors by the addition of a redox-active electrolyte.

Author(s) Lamiel, C.; Lee, Y.Rok; Cho, M.Hwan; Tuma, D.; Shim, J.J.
Journal J Colloid Interface Sci
Date Published 2017 Dec 01

Supercapacitors are an emerging energy-storage system with a wide range of potential applications. In this study, highly porous nickel-cobalt-oxide@reduced graphene oxide (Ni-Co-O@RGO-s) nanosheets were synthesized as an active material for supercapacitors using a surfactant-assisted microwave irradiation technique. The RGO-modified nanocomposite showed a larger specific area, better conductivity, and lower resistivity than the unmodified nanocomposite because the RGO facilitated faster ion diffusion/transport for improved redox activity. The synergistic effect of Ni-Co-O@RGO-s resulted in a high capacitance of 1903Fg(-1) (at 0.8Ag(-1)) in a mixed KOH/redox active K3Fe(CN)6 electrolyte. The asymmetric Ni-Co-O@RGO-s//AC supercapacitor device yielded a high energy density and power density of 39Whkg(-1) and 7500Wkg(-1), respectively. The porous structure and combination of redox couples from both the electrode and electrolyte provided a highly synergistic effect, which improved the performance of the supercapacitor device.

DOI 10.1016/j.jcis.2017.08.003
ISSN 1095-7103
Citation J Colloid Interface Sci. 2017;507:300309.

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