Characterization of Non-Aqueous Supercapacitors Based on Titanium Carbide Derived Carbon Electrodes and Novel Doubly Charged Cation Based Salts

Abstract

The electrochemical characteristics for the supercapacitors based on the titanium carbide derived carbon (CDC-TiC) electrodes in 0.4 M N,N-dimethyl-1,4-diazabicyclo[2,2,2]octanediium tetrafluoroborate (DMDABCO(BF4)2), 0.2 M DMDABCO(BF4)2 + 0.2 M triethylmethylammonium tetrafluoroborate (TEMABF4), and 0.4 M TEMABF4 in g-butyrolactone (g-BL) have been studied using cyclic voltammetry, constant current charging/discharging and electrochemical impedance spectroscopy. The ideal supercapacitor behaviour was observed in a wide region of cell voltages (U < 3.0 V) in 0.4 M DMDABCO(BF4)2 in g-BL. The geometry of solvation shell around DMDABCO2+ has been optimized with molecular dynamics calculations and the coordination number equal to 15, have been proposed and compared with electrochemical and gas sorption data for CDC-TiC. The gravimetric capacitance 129 F g-1, energy 40.6 W h kg-1 and power 93 kW kg-1 were established for the CDC-TiC electrodes in 0.4 M DMDABCO(BF4)2 g-BL solution.