The elemental N emerged uniformly in graphdiyne (GDY) after heat treatment under NH3 atmosphere to form N-doping GDY. The interplanar N-GDY distance decreased slightly, which may be ascribed to the smaller atom radius of N than C. Compared with GDY, the introduction of N atoms in N-GDY created numerous heteroatomic defects and active sites, thus achieving enhanced electrochemical properties, including higher reversible capacity, improved rate performance, and superior cycling stability. In addition, N-doping might be advantageous to minimize the surface side reactions and form stable interfaces, hence improving the electrochemical cycling stability of N-GDY electrodes. These results indicate N-doping is also an efficient way for improving the electrochemical performance of GDY materials.
Keywords: graphdiyne; lithium-ion storage; nitrogen-doped; one-atom-thick; two-dimension-layer.