A simple synthesis of nitrogen-sulfur co-doped porous carbon using ionic liquids as dopant for high rate performance Li-ion batteries

A novel nitrogen-sulfur co-doped porous carbon (NSPC) material was synthesized by using ionic liquids as the nitrogen and sulfur precursor. This material exhibited porous structure with high specific surface area (701 m(2) g(-1)) and superior nitrogen and sulfur co-doping (4.66 and 1.83 wt%, respectively), The materials was used as anode materials for Lithium-ion batteries and showed a high reversible capacity of 987.7 mAh g(-1) at a current density of 0.1 A g(-1) and a good long cycle performance (337.5 mAh g(-1) at 5 A g(-1) after 5000 cycles). The NSPC's superior electrochemical performance can be attributed to three points: (1) Excellent pore structure (surface area is 701 m(2) g(-1)). (2) Nitrogen and sulfur co-doping (4.66 and 1.83 wt%, respectively). (3) Higher rate of capacitance contribution during process of charge and discharge.