Fuel coke derived nitrogen and phosphorus co-doped porous graphene structures for high-performance supercapacitors: The trail towards a brown-to-green transition

Abstract

As the looming crisis of global energy market exponentially intensifies, the scientific community prompts the use of supercapacitors as a sustainable energy production/storage model and emission reduction strategy. Therefore, in this work, we present a cutting-edge approach for the high-value utilization of fossil fuel-derived materials in supercapacitor applications, promoting an integrated brown-to-green transition for energy, ecology, and the environment. Herein, nitrogen and phosphorus co-doped porous graphene sheets (a-NPGO) have been prepared from fuel coke, which exhibits outstanding electrochemical performance as a supercapacitor electrode material. The a-NPGO shows a high specific capacitance (322 F/g at 1 A/g) almost 11 times greater than the undoped coke-based graphene derivative. Furthermore, the symmetric supercapacitor assembled with a-NPGO-modified electrodes delivered an exceptional power density of 812 W/kg at energy density of 14 Wh/kg and an excellent capacitance retention of 90 % after 5000 charge-discharge cycles. This impression of coke-derived material in high-performance supercapacitors may broaden the horizon of the current electrochemical energy storage paradigm and afford the eco-conscious implementation of fossil fuel resources.