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.