Abstract:
Efficient energy storage devices like rechargeable
batteries have a vital role in the modern society to cater for an
ever-increasing demand of energy. In this context, magnesium-ion
batteries (MIBs) have emerged as high-capacity energy storage
systems. However, the progress in this area is hindered due to the lack
of suitable anode materials for efficient Mg2+ ion storage and
diffusion. In this study, using state-of-the-art density functional theory
(DFT) simulations, we have systematically investigated novel onedimensional Si2BN nanoribbons as anode materials for MIBs
applications. Our calculations confirm the structural stability and
metallic character of pristine (Si2BN) and hydrogen functionalized
(Si2BN-H) nanoribbons upon Mg adsorptions. We find Mg
adsorption energies in the ranges of −1.2 to −1.8 (−1.8 to −2.0)
eV for 25% (20%) coverages in Si2BN (Si2BN-H), respectively, which
are strong enough to mitigate the Mg aggregation. Maximum specific capacities of 661.865 (550.421) mAh g−1 and open-circuit
voltages of 0.7−1.1 (0.6−0.8) V are found for Si2BN (Si2BN-H), respectively. Diffusion barrier calculations based on nudge elastic
band (NEB) methods reveal a relatively low barrier of 0.14 eV, which guarantees a robust diffusion of Mg ions and faster charge/
discharge capability of Si2BN nanoribbons. These intriguing features confirm the potential of functional Si2BN nanoribbons as
promising anode materials for MIBs.
