Graphitic Carbon Nitride Nanotubes As Li-Ion Battery Materials: A First-Principles Study

First-principles calculations based on density functional theory are carried out to investigate the Li storage capability of graphitic carbon nitride nanotubes. The porous nanotubes provide unprecedented opportunity for energy storage due to their uniform size of pores in the wall and doubly bonded nitrogen at the edges of the pore. The calculations predict that the Li atoms can easily access the interior of the nanotube through the pores in the wall because of the low energy barrier and thus be stored both inside and outside of the nanotubes. The exothermic intercalation of Li further shows that g-C3N4 nanotubes are suitable for Li storage. The Li density in bundles of nanotubes is predicted to be up to 0.57 (Li4C3N4). The porous graphitic carbon nitride nanotubes are applicable in Li-ion battery with high density and stability.