Free-standing nitrogen-doped reduced graphene oxide anode for lithium-ion batteries

Graphenes have been considered suitable candidate materials for electrodes of energy storage devices such as lithium-ion batteries (LIBs) because of their outstanding mechanical, thermal and electrical properties. However, there are problems when using these carbon materials for electrodes because of their low electrochemical performance. In this work, to improve the electrochemical performances of graphenes, free-standing nitrogen-doped reduced graphene oxides (FNRGOs) were prepared as an anode for LIBs using a facile vacuum filtration method and thermal annealing at different temperatures. X-ray diffraction and X-ray photoelectron spectroscopy were employed to characterize the prepared samples, and then their electrochemical performance was investigated by galvanostatic charge/discharge (GCD) tests. GCD tests revealed that FNRGO prepared from thermal annealing at 500 degrees C exhibited good initial reversible capacity (502 mA h/g at 50 mA/g (0.14 C)) and enhanced cycle stability (capacity retention of 90.5% after 50th cycles at 100 mA/g (0.27 C), which demonstrated that FNRGOs were suitable candidates as anodes for LIBs.