Two-dimensional (2D) Sc2 C, an example of a MXene, has been attracting extensive attention due to its distinctive properties and great potential in applications such as energy storage. In light of its high capacity and fast charging-discharging performance, Sc2 C exhibits significant potential as an anode material for lithium- and sodium-ion batteries. Herein, a systematic investigation of Li/Na atom adsorption and diffusion on Sc2 C planes was performed based on density functional calculations. The metallic character of pristine and adsorbed Sc2 C ensures desirable electric conductivity, which indicates the advantages of 2D Sc2 C for lithium- and sodium-ion batteries. A significant charge transfer from the Li/Na atoms to Sc2 C is predicted, which indicates the cationic state of the adatoms. In addition, the diffusion barriers are as low as 0.018 and 0.012 eV for Li and Na, respectively, which illustrates the high mobility and cycling ability of Sc2 C. In particular, each formula unit of Sc2 C can adsorb up to two Li/Na atoms, which corresponds to a relatively high theoretical capacity of 462 or 362 mAh g-1 . The average electrode potential was calculated to be as low as 0.32 and 0.24 V for stoichiometric Li2 Sc2 C and Na2 Sc2 C, respectively, which makes Sc2 C attractive for the overall voltage of the cell. Herein, our results suggest that Sc2 C could be a promising anode candidate for both lithium-ion and sodium-ion batteries.
Keywords: density functional calculations; lithium-ion batteries; nanostructures; scandium; sodium-ion batteries.
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