Fractional-order electric double-layer capacitors with tunable low-frequency impedance phase angle and energy storage capabilities

Allagui A.
Alnaqbi H.
Elwakil A.S.
Said Z.
Hachicha A.A.
Wang C.
Abdelkareem M.A.

In this study, we report the electrical response of two sets of solid-state fractional-order electrochemical capacitors for which the low-frequency impedance phase angle can be tuned from - 69 ° to - 7 °. The configuration makes use of a gel electrolyte in which carbonaceous additives (graphite or reduced graphene oxide) are dispersed at different proportions. Such a disordered electrolyte structure results in subdiffusive charge transport and thus a frequency dispersive capacitive-resistive behavior typical of a constant phase element, which can be useful for both frequency applications and energy storage purposes. © 2020 Author(s).