Coal tar pitch derived N-doped mesoporous carbon through "carbonization in air" strategy for high performance supercapacitor electrode

In the present work, the N-doped mesoporous carbon was prepared through an easy solid phase milling and "carbonization-in-air" strategy from coal tar pitch (CTP). A novel NaCl-KCl-NaF composite salt was used as the additive and acted as a flame-retardant coating and pore template during the heating process. This strategy achieved high carbon production rates from CTP without using inert atmosphere. The prepared products were characterized by mesopores, high specific surface area (1362.26 m2 g-1), and nitrogen doping. The synthesized CKNF700-2-3 achieved a carbon yield up to 43.02 wt%, with the specific capacitance reaching 343.9 F g-1 at 1 A g-1. The CKNF700-2-3//CKNF700-2-3 symmetric supercapacitor showed the ultra-high energy density (33.4 Wh kg-1) at the 600.1 W kg-1 power density.