Nitrogen-doped graphene nanoribbons (N-GNRs) were synthesized through longitudinal unzipping of nitrogen-doped carbon nanotubes filled with iron nanowires (Fe@CNx-CNTs) by means of nitric acid oxidation. Benefiting from their N doping and edge effect, N-GNRs showed high capacity, excellent cycling performance and rate capability as anode materials in lithium ion batteries (LIBs).
