Nitrogen–Sulfur Co-Doped Porous Carbon Prepared Using Ionic Liquids as a Dual Heteroatom Source and Their Application for Li-Ion Batteries

Nitrogen–sulfur co-doped porous carbon (NSPC) were prepared by using ionic liquids as both nitrogen and sulfur source. The as-obtained NSPC exhibits open pore structure with thin carbon walls and nitrogen (2.32 wt%) and sulfur (0.91 wt%) doping. When used as lithium-ion batteries (LIBs), NSPC shows a high reversible capacity of 821 mAh g⁻¹ at 0.1 A g⁻¹ after 50 cycles. Even after 1000 cycles, the NSPC exhibits a stable reversible capacity of 533 mAh g⁻¹ at current density of 1.5 A g⁻¹. The excellent electrochemical performance of NSPC is attributed to two points: (1) interconnected three-dimensional pore structure; (2) Nitrogen and sulfur doping and the synergic effect of dual-doping heteroatoms. This work provides new ideas for the development of new anode materials for LIBs.