Synergistic Approach with Redox Additive for the Development of Environment Benign Hybrid Supercapacitor

In the present work, capacitive features of mango kernel derived active carbon-based supercapacitor with environment benign sodium acetate (1M CH3COONa) (not holding harmful F- and S-compound) and CH3COONa added K4Fe(CN)(6)-redox additive electrolyte are explored. Variety of techniques (BET, XRD, SEM, RAMAN & FTIR) are used to characterize the active material. The specific surface area from the BET method is found to be 1133 m(2) g(-1). The supercapacitor cell fabricated by using CH3COONa delivers specific capacitance and energy of 92 F/g and 7.1 Wh/Kg, respectively. Interestingly, 2-3 times enhancement in capacitance (197 F/g) and energy (18.2 Wh/Kg) are observed for the addition of K4Fe(CN)(6) into CH3COONa, which is associated with the faradaic redox reaction between [Fe(CN)(6)](-4)/[Fe(CN)(6)](-3) redox couple. For comparison purpose 1M Na2SO4 (with and without K4Fe(CN)(6)) are also used as electrolytes to fabricate supercapacitor and this comparison concludes the better capacitive performance of environment benign CH3COONa electrolytes based supercapacitors in all scenarios. Moreover, the cycle life test (for 5000cycles) and thermal effects (in the temperature range of 20 degrees C-70 degrees C) are explored for the fabricated cell. In all these test, K4Fe(CN)(6) based redox systems are found to leave its ample effect on the supercapacitor performance, positively. (C) 2019 The Electrochemical Society.