In-situ growth of CNTs-porous carbon from asphalt with superior double-layer capacitive performance

Carbon materials have been engaged in supercapacitor, but the commercial biomass and coal-based carbon were far from satisfactory due to the hard control of pore structure and inferior electric conductivity. Newly developed carbon materials or composites, such as porous graphene or CNTs based materials were suffering from high cost or hard to balance energy and power densities. Herein, we obtained a CNTs-porous carbon by directly controlling the pyrolysis process of the petroleum asphalt. The composite combined both porosity and the conductive pathways for the migration of ions and electrons. The existence of a little S, N heteroatoms contributed to the infiltration of the aqueous electrolyte. The obtained symmetric supercapacitor demonstrated a superior capacitance of 385.7 F g−1 at the current density of 1 A g−1 with 93.8% capacity retention after 10,000 cycles under 4 A g−1. This material provided an optimistic choice for high-power equipments.