Superior cycle stability of nitrogen-doped graphene nanosheets as anodes for lithium ion batteries

The specific capacity of nitrogen-doped graphene nanosheet (N-GNS) evidently increases with charge/discharge cycles, exhibiting superior electrochemical performance. N-GNS presented a specific capacity of 684 mAh g− 1 in the 501st cycles while only 452 mAh g− 1 in the 100th cycle, accounting for higher cycling stability and larger specific capacity in comparison to a pristine graphene and a commercialized graphite anode. The obtained significant improvement is attributed to the incorporated nitrogen to graphene planes with a result of more structural defects during cycling.

Graphical abstractNitrogen-doped graphene has a rippled and crumpled structure similar to the pristine graphene. It shows a higher specific discharge capacity. Its discharge capacity (up to 684 mAh g− 1 at the 501st cycle) significantly increases with the charge/discharge cycles, demonstrating excellent cycle performance for the use of N-GNS for high performance lithium ion battery application.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We report that nitrogen-doped graphene nanosheets show an enhanced specific capacity in comparison to un-doped one. ► Nitrogen-doped graphene nanosheets present a superior cycle stability as anode for lithium ion batteries. ► The improvement is ascribed to the increase in number of defect sites and vacancies as Li+ active sites on graphene. ► This simple synthetic strategy and the underlying mechanism open a door to use new nitrogen-doped graphene for lithium ion batteries.