Nitrogen-Doped Hollow Carbon Nanospheres Derived from Dopamine as High-Performance Anode Materials for Sodium-Ion Batteries

Designed as an anode material for sodium ion batteries, porous nitrogen-doped hollow carbon nanospheres (N-HCS, D = 200 nm) are successfully synthesized via the mature template-assisted method using silica and dopamine as template and carbon precursor, respectively. For detailed characterization of Raman, FTIR and XPS results, it is revealed that N-doping can form a disordered carbon structure and induce a large number of topological defects on carbon outer wall. The N-HCS electrode exhibits excellent cycling stability and rate capability, delivering a satisfying capacity of 306mAh g(-1) over 600 cycles at a discharging rate of 0.05A g(-1) and an attainable capacity of 188mAh g(-1) even at a high discharging rate of 3.0A g(-1). The excellent electrochemical performance of N-HCS can be attributed to the high content of pores. Moreover, the high content of pyridinic and graphitic N could facilitate the transfer of sodium ion and electron.