The
applicability of a two-dimensional β-antimonene (β-Sb)
monolayer as a negative electrode material for Na-, K-, and Mg-ion
batteries has been conducted through first-principles calculations
based on density functional theory (DFT). Our findings propose that
the hollow and top sites are the energetically most stable adsorption
sites for Na, Mg, and K atoms. The chronological adsorption energy,
charge transfer, open-circuit voltage, theoretical storage capacity,
and metal-ion diffusion barrier energy are investigated. The semiconducting
β-Sb monolayer can provide inherent benefits for transportation
of electrons through it, which can deliver tremendous mobility with
lower barrier energies of 0.10 eV for Na, 0.09 eV for K, and 0.15
eV for Mg for the diffusion process. The double layers of β-Sb
can adsorb ions on both sides, which leads, at high concentrations
(Na2Sb, K2Sb, and Mg2Sb), to theoretical
storage capacities of 440.22, 440.22, and 880.45 mAh/gm for Na, K,
and Mg ions, respectively. Besides, the electronic formation of β-Sb
changed the nature from semiconducting to metallic under metal-ion
adsorption, which significantly enhanced the performance of metal-ion
batteries. With the given advantages, we propose that the β-Sb
monolayer can be viewed as a potential material for negative electrodes
in Na-, K-, and Mg-ion batteries.
