Double layer capacitance for different thicknesses of carbon overlay and types of electrolytes: a circuit analogue approach

Abstract

Electrochemical double layer capacitor (EDLC) complements batteries in addressing the intermittency problems in non-renewable energy sources. Here, the charge is stored in double layer in porous materials that offer high internal surface area. At the time of charging or discharging the capacitor, the transport of ions through the pore network involves resistance that influences the effectiveness of storage. This article presents the impedance spectroscopy data to analyse the resistance inside the pore. The equivalent circuits were fitted here to explain the complex impedance curve. The resistive and capacitive elements and their arrangement were studied for different thicknesses of the activated carbon overlay. The effect of binder on the internal surface area of activated carbon powder was evaluated through BET analysis and scanning electron microscopy. The results were compared for two electrolytes. Aqueous solution of potassium chloride as an aqueous electrolyte, and tetra ethyl ammonium tetra fluoroborate in acetonitrile as an organic electrolyte were used in this study.

Theoretical and experimental studies of imidazolium based ionic liquids for supercapacitors application

“…Electrolytes initiate the electrical energy in electrochemical cells by allowing the chemical reaction in it (Jiang, Hu, Yan & Wu, 2017). The conversion of chemical energy to electrical energy occurs in electrolytes before passing to the surface of the electrode (Singh, Rakib, Chavhan & Ganguly, 2016). With these critical initiatives in the electrolyte, makes the electrolytes act as the heart of the electrochemical system.…”