A Density Functional Theory Study on Rechargeable Mg‐ion Batteries: C 20 Fullerene as a Promising Anode Material

Abstract In this study, the applicability of C 20 fullerene as anode material in Mg‐ion batteries was investigated by Density Functional Theory (DFT). The interaction energy of the Mg 2+ ion on C 20 structure was found as −147.3 kcal/mol. The HOMO‐LUMO gap value decreased during Mg interaction on C 20 structure while it increased during Mg 2+ interaction. The charge distributions obtained after the interactions of Mg atoms on C 20 show that charge transfer has taken place. The storage capacity value of C 20 structure was calculated to be 893 mAhg −1 . The diffusion barrier was calculated as 1.9 kcal/mol. In addition, the diffusion coefficient for Mg and Mg 2+ on C 20 structure were computed as 1.5×10 −25 and 4.61×10 −4 , respectively. Consequently, the high storage capacity, high conductivity and low diffusion barrier for discharge/charge process and the suitability of the diffusion coefficient suggest that C 20 fullerene structure can be used as a potential anode material in rechargeable Mg‐ion batteries.