N doped porous carbon derived from coal tar pitch for supercapacitor and zinc ion hybrid capacitor

Coal tar pitch (CTP) is widely used in road laying. However, how to realize its high added value is still a difficult problem to be solved. Herein, we report the simple avenue for the synthesis of N doped porous carbon (NPC Mg ) by template method derived from aromatic hydrocarbons in CTP. The NPC Mg presents big surface area of 2523.2 m 2  g −1 and hierarchical pore structures, temperate N content of 1.88 at.%. Due to the structural merits, NPC Mg electrode obtains large capacitance of 483.1 F g −1 at 0.1 A g −1 and superb cycle stability with 4.6% decay after 25,000 cycles in 6 M KOH solution. Besides, NPC Mg -based supercapacitor with neutral electrolyte also achieves high capacitance of 339 F g −1 , large energy output of 33.3 Wh kg −1 , long cycle life without decay after 15,000 cycles. Interestingly, the NPC Mg -based zinc ion hybrid capacitor presents large capacity of 287.7 F g −1 and superb energy output of 114 Wh kg −1 . This work provides a common approach to synthesize heteroatom doped carbon materials for capacitors.