Tuning the electronic properties of SiC nanosheets decorated by Lin (n = 1–3) for the anode of lithium-ion batteries

Abstract

In the present work, DFT calculations were carried out to investigate the electronic and structural properties of two six-membered 7-rings (A) and 19-rings (B) Li-decorated silicon carbide nanosheets (Li1-3-SiCNSs) at M06-2X/6-31+G(d) and B3LYP/6-31+G(d) levels of theory. The binding energies for pristine SiCNSs, adsorption energies for Li1-3-decorated SiCNSs, bond gap energies, the density of states (DOS), dipole moment, charge transfer values and global reactivity descriptors were explored. The results show that complexes containing two neighbouring Li atoms (A1,7 and B1,7 ) are more stable than other ones. The three Li atoms in cluster A tend to form the Li-Li bond, while in cluster B they tend to be apart from each other. The positive potential Vcell values (1.67 V for A1 and 1.96 V for B1 ) reveal that the Li@SiC → Li+@SiC oxidation process can be energetically a favourable half-reaction. This makes that the SiCNSs be a promising candidate for use as the anode material in the Lithium-Ion Batteries. DOS graphs show that Li1-SiCNS and Li3-SiCNS are magnetic materials with different spin polarisation properties. The total magnetic moment of Li1- and Li3-decorated SiCNSs is predicted to be 1.0 μB.