A DFT study on nanocones, nanotubes (4,0), nanosheets and fullerene C60 as anodes in Mg-ion batteries

Abstract

In this article, we studied the interactions between Mg atom and Mg²⁺ ion and four nanostructures, including a nanocone, nanotube (4,0), nanosheet, and C₆₀ nanocage, to obtain the cell voltages (V) for Mg-ion batteries (MIBs). Total energy, geometry optimization, frontier molecular orbital (FMO) and density of states (DOS) analyses have been performed using the ωB97XD level of theory and the 6-31G(d) basis set. The DFT calculations clarified that the changes in energy adsorption between Mg²⁺ ion and the nanostructures, E_ad, are in the order tube > cone > sheet > cage. However, V_cell for the nanocone is the highest. The changes in V_cell of the MIBs are in the order cone > tube > sheet > cage. This study theoretically considers the possibilities of Mg as an anode in batteries due to its high V_cell values.