  B$_5$Se this work we investigate the Li adsorption properties of a hybrid 2D
material, namely monolayer B5Se with first principles calculations. 2
dimensional B$_5$Se was found to have a distorted hexagonal structure with five
B atoms and one Se atom at the vertices of each hexagon. The density functional
theory (DFT) calculations are performed with the generalized gradient
approximation (GGA) and Perdew-Burke-Ernzerhoff (PBE) exchange correlation
functional. The results were inclusive of van der Waals corrections with
Grimmes DFT-D2 scheme. Electrode performance metrics, as the most preferred
adsorption sites and adsorption energies, open circuit anode potentials, charge
density differences and specific capacities for varying adatom coverage were
evaluated with the DFT calculations. The adatom diffusion barriers were
evaluated with a nudged elastic band (NEB) method. The ab-initio calculations
predict a maximum theoretical specific capacity of 1486.87 mAhg$^{-1}$ for Li
adsorption on 2D B$_5$Se, which is over four times that of conventional Li ion
battery anode materials. This coupled with an open circuit anode potential of
0.291-0.179V for different degrees of Li coverage, and a small Li diffusion
barrier of 0.15eV, metallic nature of the sheet under pure and lithiated
conditions and good charge density variations, make monolayer B$_5$Se a potent
anode material for Li-ion battery applications.
