Enhanced Capacitive Performance of N-Doped Activated Carbon from Petroleum Coke by Combining Ammoxidation with KOH Activation

Abstract

Low cost with high specific capacitance and energy density is the critical and main requirement for practical supercapacitors. A novel N-doped activated carbon was fabricated by KOH activation of petroleum coke and ammonia treatment. The as-prepared carbon exhibits a high specific surface area (1875 m2 g−1), excellent conductivity (57 S m−1), and rich nitrogen level (4.0 wt%). Those outstanding characters result in this porous carbon a hopeful electrode material for electrochemical supercapacitors. It shows high specific capacitance (up to 299 F g−1) and superior rate capability (76 % retention ratio at 20 A g−1) in 30 wt% KOH aqueous electrolyte. This efficient treatment method ensures its prosperous application in energy storage systems.