A first principles study of corundum V₂O₃ material as a promising anode for Li/Mg/Al-ion batteries

Rechargeable multivalent metal-ion batteries have attracted the attention of researchers, owing to their great potential to meet the future demands from portable devices to large-scale energy storage. This is mainly due to their natural abundance, high safety levels, and high energy density. In this work, we study the thermodynamic, electronic, and structural properties, and the variation in the open-circuit voltage during the insertion of Li, Mg and Al atoms into corundum V₂O₃ using first principles calculations. The formation energies of fully lithiated LiV₂O₃, magnesiated Mg_0.5V₂O₃, and aluminiated Al_0.5V₂O₃ systems are all negative, indicating the possibility of introducing Li/Mg/Al atoms into V₂O₃ spontaneously. Furthermore, we have shown that the open circuit voltage of Li⁺ starts with a value of 2.04 V, which is in good agreement with the experimental results. On the other hand, it takes a lower value equal to 0.31 and 0.41 V for Mg²⁺ and Al³⁺ respectively, which is required for negative electrode materials. The maximum theoretical capacity of V₂O₃ is 1072 mA h g^-1 for magnesium-ion batteries (MIBs) and 1679 mA h g^-1 for aluminum-ion batteries (AIBs). Based on these calculated properties, we can propose corundum V₂O₃ as a promising negative electrode for Mg/Al-ion batteries.