Redox-ambitious route to boost energy and capacity retention of pouch type asymmetric solid-state supercapacitor fabricated with graphene oxide-based battery-type electrodes

Abstract On the way to swift faradaic charge transfer rate of supercapacitor (SCs), it is an essential to take next step toward the fabrication of all-solid-state asymmetric supercapacitor with redox active mediators. Herein, innovative hybrid positive rGO/NiCo2O4@MnO2 (R-NCO150@MN) and negative rGO/Bi2O3@Cu2S (R-BOPEG140@CS) electrodes based on reduced graphene oxide (rGO) with core-shell structured battery-type electrodes are synthesized by chemical methods. Moreover, new design of all-solid-state SCs are fabricated using the polyvinyl alcohol-potassium hydroxide composite with the addition of K3[Fe(CN)6] mediator to eliminate drawbacks of aqueous based asymmetric SCs. Cs of 2107 F g−1 and 1617 F g−1 are achieved at 5 mV s−1 for the positive and negative electrodes respectively. The fabricated all-solid-state asymmetric SCs widen the potential up to 2.1 V with a higher energy density of 60.52 Wh kg−1 at a power density of 625 W kg−1 and a capacity retention of 95.17% over 10,000 charge/discharge cycles. Demonstrations of series connected asymmetric solid-state supercapacitor (ASCs) with LEDs (white, blue, green, yellow and red), 131 parallel connected red LEDs, 193 yellows and green LEDs as well as digital stopwatch (goes more than 30 min after 10 s charge) supports to commercialization of the present ASCs.