Chemical blowing strategy synthesis of nitrogen-doped hierarchical porous carbon from coal tar pitch for high-performance lithium-ion batteries

A facile and green chemical blowing strategy is proposed for preparing hierarchical porous carbon (N-PHPC-X) from coal tar pitch (CTP) under the assistance of (NH4)2SO4. The structural features and electrochemical properties of N-PHPC-X with different levels of nitrogen doping (N-doping) were analyzed and tested. The results show that N-doping is an effective approach to enhance electrical conductivity, strengthen reversibility of reactions, and facilitate rapid lithium storage by introducing rich defects and functional groups into the carbon framework. The optimal N-PHPC-4 with hierarchical micro-mesoporous structures possesses moderate specific surface area of 581 m2 g−1 and large pore volume of 0.980 cm3 g−1. As an anode for lithium-ion batteries (LIBs), it provides an excellent reversible specific capacity of ~ 620 mAh g−1 at 100 mA g−1 after 200 cycles. More importantly, this strategy is more environmentally friendly and holds a great prospect for realistic application.