Synergy of interlayer expansion and capacitive contribution promoting sodium ion storage in S, N-Doped mesoporous carbon nanofiber

Heteroatoms doping is proved to be an effective strategy to improve the electrochemical performance of carbon materials by adjusting its physical and chemical properties. In this work, sulfur, nitrogen co-doped carbon nanofiber (SNCNF) is prepared by electrospinning technique with the following heat and hydrothermal treatment route. Benefiting from the S, N co-doping, SNCNF demonstrates perfect pseudocapacitance characteristic improving rate performance (N-doping) and large interlayer distances promoting reversible insertion/extraction of Na+ (S-doping). SCNNF displays high charge-discharge specific capacity (290.3 mA h g−1 at 0.1 A g−1), superior cycling stability (247.4 mA h g−1 and 98.2% retention at 0.5 A g−1 over 600 cycles) and ultra-long circulation characteristics at high current rate (160.2 mA h g−1 at 10.0 A g−1 after 10,000 cycles), which can be served as a very promising material as anode for sodium ion batteries.