Free-standing honeycomb-like N doped carbon foam derived from coal tar pitch for high-performance supercapacitor

Abstract A free-standing honeycomb-like N doped carbon foam (FHNC) is fabricated by one-step carbonization and activation of the commercial melamine foam loading coal tar pitch and KOH. The as-prepared FHNC exhibits the three-dimensional (3D) interconnected architecture with hierarchical honeycomb-like structure, which has a large specific surface area of 3105 m2 g−1. The specific capacitance of FHNC reaches up to 280.3 F g−1 at 1 A g−1, and still maintains 185.4 F g−1 at 40 A g−1, indicating the excellent rate capability. Additionally, the assembled symmetrical supercapacitor demonstrates the maximum energy density of 10.1 Wh kg−1 at a power density of 250 W kg−1, and excellent cycling stability (96.3% capacitance retention after 10,000 charge-discharge cycles at 5 A g−1). The outstanding electrochemical performance is assigned to the unique 3D interconnected architecture that endow the large accessible surface area, and rapid transfer pathway for ion and electron.