Petroleum coke is a valuable and potential source for clean energy storage if it could be modified legitimately and facilely. In the present study, porous carbon with high surface area and abundant oxygen-containing groups was prepared from petroleum coke by chemical activation and modification processes. The as-prepared carbon exhibits a high surface area (1129 m2 · g−1) and stable micrographic structure. It presents a high specific capacitance and excellent rate performance in KOH electrolyte. Even at an ultrahigh current density of 50 A · g−1, the specific capacitance of the prepared carbon can still reach up to an unprecedented value of 261 F · g−1 with a superhigh retention rate of 81 %. In addition, the energy density of this material in aqueous electrolyte can be as high as 13.9 Wh · kg−1. The high energy density and excellent rate performance ensure its prosperous application in high-power energy storage system.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.