▎ 摘　　要

Growing demands for rechargeable batteries have promoted the design of high-performance electrode materials. Based on first-principles calculations, we investigate the selected B-doping C3N monolayer as an alternative anode material for Li-, Na-, and K-ion batteries. Doping substrates have provided higher adsorption energy for alkali metal atoms than that of pristine substrate. The electron loss of C3N monolayer caused by B-doping will strengthen the adsorption of alkali metal atoms on the system, and prevent the cluster formation of alkali metal atoms. Therefore, it can improve the recycle stability of alkali metal ion batteries. More interestingly, compared with the pristine C3N monolayer, the B-4-doped C3N systems have an enhanced specific capacity for these alkali metal atoms. Furthermore, the B-4-doped C3N substrates with the adsorption of alkali metal atoms have highly thermal stabilities verified by ab-initio molecular dynamics simulations. The diffusion barriers of Li, Na and K atoms on the B-4-doped C3N systems have slightly increase, which are still smaller than the threshold (0.5 eV) for metal migration at room temperature. These above analysis indicate that the B-doping in the C3N monolayer can improve its performance as an anode material for alkali metal ion batteries.