C3N/blue phosphorene heterostructure as a high rate-capacity and stable anode material for lithium ion batteries: Insight from first principles calculations

Two dimensional heterostructures could not only combine each other's advantages, but also compensate for their drawbacks. In this work, we systematically investigated the C3N/blue phosphorene (C3N/BlueP) heterostructure as an anode material for Li-ion batteries (LIBs) based on the comprehensive first principles computations. Our results show that the C3N/BlueP heterostructure possesses good structural stability and ultra-high stiffness (Y-x = 417.3 N/m). The band gap of C3N/BlueP heterostructure is 0.026 eV, exhibiting good electrical conductivity for fast electron transport. Attributed to the synergistic effect, the adsorption energy of Li in the interface region of C3N/BlueP heterostructure (-2.057 to -1.898 eV) is greatly increased in comparison with pristine C3N (-0.563 eV) and BlueP (-1.852 eV). Consequently, the specific capacity is up to 1092 mA h/g, which far exceeds those of other BlueP-based heterostructures and commercial graphite (372 mA h/g). Additionally, the diffusion barrier for the C3N/BlueP heterostructure is only 0.12 eV, implying fast Li migration. Given these exceptional properties, that is, good electrical conductivity, ultra-high stiffness, high specific capacity and low diffusion barrier, it could be concluded that the C3N/BlueP heterostructure is an appealing anode material for high-performance LIBs.