Graphene-like AlP3 monolayer: A high-performance anode material for Li/Na/K-ion batteries

The rational design of anode materials with high capacity, good stability, and fast diffusion rate are crucial demands for rechargeable alkali metal ion batteries (AMIBs). Herein, the density functional theory calculations have been carried out to investigate the feasibility of an AlP3 monolayer with folded graphene-like structure as an anode material for AMIBs. The results indicated that the alkali metal atoms (AM = Li, Na, and K) can be stably adsorbed on the AlP3 monolayer surface and further enhance the conductivity of the system. The average open-circuit voltages are only 0.70 V, 0.28 V, and 0.37 V for Li, Na, and K storages, respectively. The diffusion energy barriers of Li, Na, and K atoms are 0.56 eV, 0.41 eV, and 0.20 eV, respectively. Furthermore, the AlP3 monolayer possesses a high theoretical specific capacity of 447 mAh g−1, 894 mAh g−1, and 1565 mAh g−1 for Li, Na, and K-ion batteries, respectively. Overall, the AlP3 monolayer is an excellent anode material for AMIBs, especially for K-ion batteries.