Potential application of two-dimensional PC6 monolayer as an anode material in alkali metal-ion (Li, Na, K) batteries

The development of two-dimensional (2D) materials in anode has been believed as a significant research di- rection to promote the innovation of alkali metal-ion batteries. Lately, PC6 monolayer, a neoteric material, has stimulated people's research enthusiasm owing to its outstanding thermodynamic and electrical natures. In this paper, by employing the first-principles calculation method based on density function theory, the feasibility of PC6 monolayer acting as an anode in alkali metal-ion batteries has been systematically evaluated. The simulation results indicate that, when acting as anode material, the PC6 monolayer can not only provide effective adsorption interaction for metal ions which is beneficial for inhibiting the formation of clusters, but also can furnish satisfactory storage capacity (1496.23 mA center dot h center dot g-1 for Li, 1301.07 mA center dot h center dot g-1 for Na, and 780.63 mA center dot h center dot g-1 for K). Meanwhile, PC6 monolayer can supply appropriate average open-circuit voltages (0.48/0.40/0.64 V for Li/Na/ K), which are all within the ideal voltage range of anode material. Importantly, the appraised diffusion behaviors further reflect the isotropic property and wonderful migration performance (0.42/0.46/0.29 eV for Li/Na/K) of PC6 monolayer for metal ions. Remarkedly, the ab initio molecular dynamics simulations results illustrate that these saturated adsorption systems have excellent deformation resistance at a high temperature of 400 K. These exciting performances endow the PC6 monolayer with promising application prospects as an anode in alkali metal-ion batteries.