Graphene oxide templated nitrogen-doped carbon nanosheets with superior rate capability for sodium ion batteries

Doping of N atoms into the carbonacous materials can generate extrinsic defects and more active sites, improve electrode wettability and also broaden the interlayer distance of carbon, hence promote Na storage capacity and high rate capability. Herein, we report the nitrogen-doped carbon nanosheets materials (PPyCs) obtained from pyrolysis of Polypyrrole coated graphene oxides. The pyrolysis temperature plays an important role on the electrochemical performance of PPyCs. With thermal treatment at 400, 600 and 800 °C, PPyCs have different content of N doping, and the doped N shows different existential forms. The PPyCs thermal treated at 600 °C (PPyC-600) exhibit a reversible capacity of 388.8 mA h g−1 at a current density of 100 mA g−1, and even at a high current density of 10 A g−1, high capacity of 198.6 mA h g−1 is maintained after 10,000 cycles, demonstrating outstanding cyclic stability, and high-rate capability. Furthermore, the assembled NVP/PPyC-600 full-cell demonstrates a high capacity of 122.2 mA h g−1 at a current density of 100 mA g−1 after 100 cycles, indicating the practical application of PPyCs nanosheets anode in sodium ion batteries.

Graphical abstractNitrogen-doped carbon nanosheets materials are prepared from pyrolysis of Polypyrrole coated graphene oxides. We analyze the existential form of doped N in carbon nanosheets under different annealing temperature and the influence of the content of different N species on the electrochemical performance of carbon anodes for SIBs. Importantly, the N-doped carbon nanosheets demonstrate outstanding cyclic stability and high-rate capability for SIBs.Download high-res image (409KB)Download full-size image