Dopamine derived nitrogen-doped carbon sheets as anode materials for high-performance sodium ion batteries

Designed as an anode material for sodium ion batteries, nitrogen-doped carbon sheets (NCSs) were successfully synthesized using graphene and dopamine as template and carbon precursor, respectively. The NCSs demonstrate high reversible capacity and excellent rate performance, delivering a high reversible capacity of 382 mAh g−1 at 50 mA g−1 after 55 cycles. Even up to 10 A g−1, a rate capacity of 75 mAh g−1 can be obtained. Furthermore, NCSs also have remarkable cycling stability with specific capacity of 165 mAh g−1 after 600 cycles (under 200 mA g−1). The excellent performance of NCSs can be ascribed to the nitrogen-doped two-dimension sheet structure.