Physical and electrochemical characteristics of supercapacitors based on carbide derived carbon electrodes in aqueous electrolytes

摘要

FIB-SEM, XPS and gas adsorption methods have been used for the characterisation of physical properties of microporous carbide derived carbon electrodes prepared from Mo_2C at 600℃ (noted as CDC-Mo_2C). Cyclic voltammetry, constant current charge/discharge, and electrochemical impedance spectroscopy have been applied to establish the electrochemical characteristics for supercapacitors consisting of the 1 M Na_2SO_4, KOH, tetraethyl ammonium iodide or 6M KOH aqueous electrolyte and CDC-Mo_2C electrodes. The N_2 sorption values obtained have been correlated with electrochemical characteristics for supercapacitors in various aqueous electrolytes. The maximum gravimetric energy, E(max), and gravimetric power, P_(max), for supercapacitors (taking into consideration the active material weight) have been obtained at celt voltage 0.9 V for 6 M KOH aqueous supercapacitor (E(max) - 5.7 Wh kg~(-1) and P(max) -43 kWkg~(-1)). For 1 M TEAI based SC somewhat higher E(max) (6.2Whkg~(-1)) and comparatively low P(max) (7.0kWkg~(-1)) have been calculated.