Nitrogen-doped hollow carbon nanospheres derived from dopamine as high-performance anode materials for sodium-ion batteries

Abstract

Designed as an anode material for sodium ion batteries, porous nitrogen-doped hollow carbon nanospheres (N-HCS, D=200nm) 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.