Graphene-like C3N/blue phosphorene heterostructure as a potential anode material for Li/Na-ion batteries: A first principles study

Blue phosphorene (blue-P) possesses superior adsorption capability to Li/Na atoms and its puckered graphene-like surface can provide sufficient space for Li/Na storage. However, its wide bandgap, low stiffness and chemical sensitivity restrict its further application as anode in Li/Na-ion batteries (LIBs/NIBs). Recently, the novel C3N monolayer with great mechanical, thermodynamic and electrical properties has been synthesized. Thus, we construct the C3N/blue-P (C3N/P) heterostructure consisting of C3N monolayer and blue-P monolayer to overcome the inherent defects in blue-P. The geometric, mechanical, electronic and electrochemical properties of C3N/P as anode material in LIBs/NIBs have been systematically studied by the first-principle computations. Our computations show that compared with blue-P monolayer, the C3N/P has better mechanical properties, lower band gap and stronger adsorption energy for Li/Na. Furthermore, it is predicted that the C3N/P has low diffusion barriers of 0.17 and 0.10 eV, low open circuit voltage of 0.54 and 0.35 V and high theoretical specific capacities 333 and 658 mAh/g for Li and Na, respectively. All of these characteristics ensure that the C3N/P could serve as an ideal anode material for LIBs/NIBs, especially for NIBS.