Electrochemical behaviour of hybrid devices based on Na2SO4 and Rb2SO4 neutral aqueous electrolytes and carbon electrodes within wide cell potential region

Focused ion beam scanning electron microscopy (FIB-SEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller gas adsorption methods have been used for the characterisation of physical properties of microporous carbide-derived carbon electrodes, prepared from Mo2C at 600 A degrees C (noted as Mo2C-CDC) before and after electrochemical tests conducted within a very wide two-electrode cell potential region. Cyclic voltammetry, constant current charge/discharge and impedance data have been analysed to establish the electrochemical characteristics of the hybrid devices consisting of the 1 M Na2SO4 and 1 M Rb2SO4 aqueous electrolytes and Mo2C-CDC electrodes within the very wide cell potential region (Delta E a parts per thousand currency signaEuro parts per thousand 2.4 V). The influence of cation chemical composition on the electrochemical characteristics of supercapacitors/electrochemical hybrid devices has been analysed. The complex kinetics behaviour of completed devices (adsorption, blocking adsorption and intercalation of Na+ and Rb+ ions; faradic and mass transfer; gas adsorption; etc.) has been established at Delta E a parts per thousand yenaEuro parts per thousand 1.5 V. At least three different characteristic time constants dependent on the electrolyte cation composition and cell potential applied have been established.