Functionalization of Petroleum Coke-Derived Carbon for Synergistically Enhanced Capacitive Performance

Abstract

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.