Theoretical investigating of graphene/antimonene heterostructure as a promising high cycle capability anodes for fast-charging lithium ion batteries

Alloy Sb as an anode material for Li ion batteries (LIBs) suffers from severe volume expansion and structural breakdown during lithiation process, leading to a abrupt drop of battery cycle performance. The density functional theory is used to explore the adsorption and diffusion of Li atom in the two dimensional graphene/beta-antimonene (G/Sb) heterostructure. Our calculation results reveal that the G/Sb heterostructure possesses excellent thermodynamic and dynamic stability with the 0.06 eV band gap, which is much smaller than that of monolayer Sb (1.24 eV) and can insure fast electron transport in the electrode during lithiation/delithiation process. The calculated smaller Li diffusion energy barrier and volume expansion, together with the larger Li diffusion coefficient at 300 K explore greater charge/discharge performance for the G/Sb heterostructure than the corresponding parent bulk, monolayer, and bilayer materials. This is mainly because the monolayer beta-Sb within the G/Sb heterostructure can render larger strain compared with that of the pristine beta-Sb. We also evaluate the performance of the G/Sb heterostructure as the anode of LIBs by charge analysis and density of states. These results provide conclusive evidence to explore that the G/Sb heterostructure should be a promising candidate anode for flexible and wearable LIBs.