Influence of Separator Thickness on the Performance of Electric Double Layer Supercapacitors in Aqueous Electrolyte

Abstract:

The effects of the separator thickness (δ) upon the equivalent series resistances (ESR) and specific capacitances (C_s) of supercapacitors electrodes have been investigated using commercially available porous filter paper (δ=150 μm, pores size=7.5 μm, 80 gm^-2). Commercial activated carbon electrodes immersed in 1molL^-1 KOH electrolyte (25°C) have been employed in this study. The specific capacitances were calculated from cyclic voltammetry curves at room temperature employing various scan rates (5, 10, 15 and 30 mVs^-1). Internal series resistances of the supercapacitors were measured using the galvanostatic charge discharge curves also at room temperature. A maximum of 28 separators (δ=4200 μm) have been employed in this investigation. It has been shown that the ESR increases substantially with separator thickness (from 3.1 to 7.9 Ωcm²). The specific capacitance decreased somewhat with increasing separator thickness and scan rates (from 64 to 52 Fg^-1; at 5 mVs^-1). The microstructures of the electrode material have been investigated using scanning electron microscopy (SEM) and chemical microanalyses employing energy dispersive X-ray analysis (EDX). A compositional and morphological evaluation of these electrodes showed a very homogeneous microstructure.

• Periodical: Materials Science Forum (Volume 1012)
• Pages: 109-113
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1012.109
• Online since: October 2020
• Authors: D.V. Silva*, G.S. Galdino, Lusinete Pereira Barbosa, J.C.S. Casini, R.N. Faria
• Keywords: Energy Storage, Equivalent Series Resistance, Specific Capacitance, Supercapacitors

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