Remarkable-cycle-performance β-bismuthene/graphene heterostructure anode for Li-ion battery

Remarkable Li-ion battery (LIB) anode materials need to have long cycle life and fast charge/discharge rate, however they are difficult to be realized in the monolayer anode materials. The monolayer β-Bi has the stiffness of only 33.0 N/m, thus the Bi/G heterostructure is proposed to improve the electronic and mechanical properties and to produce better LIB anode performance in this paper. The calculated results show that Bi/G heterostructure has excellent thermodynamic, dynamical and mechanical stability. The band gap is only 0.04 eV, which ensures remarkable electrical conductivity. In addition, the Bi/G heterostructure has higher stiffness (369.2 N/m) than that of monolayer β-Bi and graphene. The diffusion barrier (Ebarrier) of 0.32 eV and volume expansion ratio (VER) of only 4% can ensure the rapid transport of Li+ ions in the charge/discharge cycling process and long life of the LIB. These calculated theoretical results for describing the detail properties of Li storage and diffusion in the Bi/G heterostructure can supply adequate conclusive evidence for the prediction of remarkable properties of Bi/G heterostructure as an anode material for LIBs. [Display omitted] In this paper, we report that the two-dimensional β-bismuthene/graphene(Bi/G) heterostructure is a good anode material for Li-ion batteries. It has the advantages of small diffusion energy barrier(0.32 eV), low average open circuit voltage(0.32 V) and small volume expansion ratio(4%). Our results will support conclusive evidence to prove that the Bi/G heterostructure should be the promising LIB anode.