Nitrogen-doped porous carbon was prepared from peony shell for the cathode material of lithium‑sulfur battery

Abstract A kind of nitrogen‑oxygen dual-doped porous carbon (NOPC) was successfully prepared from biomass waste peony shell by a simple carbonization and activation. Three kinds of N and O dual-doped materials were prepared by the ratio of different carbon materials to urea, among which the NOPC-2 has ultra-high specific surface area (3177 m2 g−1), high pore volume (1.994 cm3 g−1), high mesoporous ratio(31%) and appropriate N,O co-doping. Then, the NOPC-2/S was prepared by co-thermal melting of NOPC-2 with sulfur, and the NOPC-2/S cathode showed excellent electrochemical properties in lithium sulfur battery. The capacity of NOPC-2/S with sulfur content of 70.1% was 618mAhg−1 after 200 cycles at 0.2C and remained a reversible capacity of 449.3 mAhg−1, even after 400 cycles at 1C with only 0.085% capacity fade per cycle. Its excellent electrochemical performance is mainly attributed to its high mesoporous ratio and N,O co-doping.