C3N/phosphorene heterostructure: a promising anode material in lithium-ion batteries

C3N has attracted much attention as an anode material for lithium-ion (Li-ion) batteries, owing to its excellent mechanical and electronic properties. However, its weak Li adsorption strength and mobility have limited its further application. Phosphorene (P) exhibits a high bonding strength with Li and excellent Li-ion mobility, but low stiffness. Thus, we propose that constructing a C3N/P hybrid material will not only negate the deficiency of C3N but also result in a new high performance electrode material. A C3N/P heterostructure is constructed and studied by first-principles calculations. This heterostructure exhibits an excellent stiffness (Young's modulus is 448.32 N m(-1)), which is even better than that of graphene. The bonding strength of Li inserted into the intralayer of the C3N/P heterostructure (1.78-2.02 eV) is much higher than that in pristine monolayer C3N (0.32 eV) and phosphorene (1.67 eV). Moreover, the C3N/P heterostructure shows a high capacity of 468.34 mA h g(-1), and better conductivities of electricity and ions than pristine monolayer C3N. The excellent mechanical properties, high capacity, good conductivities of electrons and ions and moderately high bonding energy indicate that the C3N/P heterostructure is a promising anode material for lithium-ion batteries.