A melt route for the synthesis of activated carbon derived from carton box for high performance symmetric supercapacitor applications

Activated carbon materials have been playing a significant role in addressing the challenges posed with the ever-increasing demand for alternative clean and sustainable energy technologies. In the present study, a facile strategy is proposed for generating porosity in porous carbons by using carton box as the precursor and eutectic NaOH-KOH melt as the activating agent. The prepared carbon materials have a very high specific surface area up to 2731 m2 g−1 with large pore volume of 1.68 cm3 g−1, which is greater than that of only KOH was used at the same mass ratio. Electrochemical studies based on symmetric supercapacitor devices demonstrating that the NaOH-KOH melt activated porous carbon exhibits significantly improved rate capability in the range of 0.5-75 A g−1 despite of the similar specific capacitance with respect to KOH activated carbon at a low current density of 0.5 A g−1. The remarkable deviations in capacitive behavior at high current density for the NaOH-KOH melt activated porous carbon and KOH activated samples highlighting the specific surface area is not the only parameter that determines the capacitive performance especially at high charge-discharge rate.