Eco-friendly, low-cost activated carbons are useful in supercapacitors, but exhibit low power-output density with high resistance. Naturally occurring electrolytes were assessed in supercapacitors here. An activated carbon/carbon nanofiber (AC/CNF) composite electrode was evaluated using natural Dead Sea water (DSW) in comparison with 6.0 M KOH, and 1.0 M H₂SO₄. Specific capacitance (C_s), energy density (E_d) and power density (P_d) were analysed, focusing on Electrochemical Impedance Spectroscopy (EIS). At 5 mV/s scan rate, cyclic voltammetry showed highest C_s 157.8 F/g for 6.0 M KOH, but differences diminished at higher-scan rates. Galvanostatic charge/discharge revealed that DSW achieved highest C_s of 81.4 F/g at 0.4 A/g. Electrochemical impedance spectroscopy indicated that DSW exhibited lowest equivalent-series resistance at 0.68 Ω and highest knee frequency (f₀ = 0.125 Hz), demonstrating rapid resistive-to-capacitive behaviour transition with cycling stability. The results confirm DSW as a useful sustainable effective alternative to synthetic electrolytes in supercapacitor applications.

Title

Chemical Papers

Publisher

Springer

Publisher Country

United States of America

Indexing

Thomson Reuters

Impact Factor

2.5

Publication Type

Both (Printed and Online)

Volume

--

Year

2026

Pages

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