Flat borophene films as anode materials for Mg, Na or Li-ion batteries with ultra high capacities: A first-principles study

TL;DR

This study uses first-principles simulations to demonstrate that flat borophene films can serve as high-capacity, stable anode materials for Mg, Na, and Li-ion batteries, outperforming other 2D materials.

Contribution

It introduces the potential of flat borophene films as ultra high-capacity anodes for various ion batteries, with detailed computational analysis of their properties.

Findings

Ultra high capacities of 2480 mAh/g for Mg-ion batteries

Flat borophene exhibits excellent electrical conductivity and thermal stability

Outperforms buckled borophene and other 2D materials

Abstract

Most recent exciting experimental advances introduced buckled and flat borophene nanomembranes as new members to the advancing family of two-dimensional (2D) materials. Borophene, is the boron atom analogue of graphene with interesting properties suitable for a wide variety of applications. In this investigation, we conducted extensive first-principles density functional theory simulations to explore the application of four different flat borophene films as anode materials for Al, Mg, Na or Li-ion batteries. In our modelling, first the strongest binding sites were predicted and next we gradually increased the adatoms coverage until the maximum capacity was reached. Bader charge analysis was employed to evaluate the charge transfer between the adatoms and the borophene films. Nudged elastic band method was also utilized to probe the ions diffusions. We calculated the average atom adsorption energies and open-circuit voltage profiles as a function of adatoms coverage. Our findings propose the flat borophene films as electrically conductive and thermally stable anode materials with ultra high capacities of 2480 mAh/g, 1640 mAh/g and 2040 mAh/g for Mg, Na or Li-ion batteries, respectively, which distinctly outperform not only the buckled borophene but also all other 2D materials. Our study may provide useful viewpoint with respect to the possible application of flat borophene films for the design of high capacity and light weight advanced rechargeable ion batteries.