Supercapacitors Based on Propylene Carbonate with Addition of Sulfur Containing Organic Solvents

Abstract

The electrochemical characteristics of electrical double layer capacitors consisting of the mainly microporous titanium carbide derived carbon (TiC-CDC) electrodes in 1 M (C2H5)3CH3NBF4 solutions in propylene carbonate (PC) and mixtures of PC with diethyl sulfite (DES) or 1,3-propylene sulfite, (PS) at different volume ratios have been studied using cyclic voltammetry, electrochemical impedance spectroscopy, constant current charge/discharge and constant power methods. The specific capacitance, phase angle and other values dependent on the solvent system used and temperature applied (from -45 ºC to 60 ºC) have been established. The region of ideal polarizability DE ≥ 2.7 V has been demonstrated for TiC-CDC electrodes in all mixed non-aqueous electrolytes and at temperatures investigated. Specific conductivity values have been obtained and correlated with the electrochemistry data. The limiting capacitance, the characteristic time constant and complex power and energy values calculated depend noticeably on the solvent mixture used, i.e., on the specific conductivity of electrolyte solution.