Metallic Monolayer Ta2CS2: An Anode Candidate for Li+, Na+, K+, and Ca2+ Ion Batteries

Exploiting two-dimensional (2D) metallic electrodes with high energy density and fast rate performance is crucial in rechargeable ion batteries. Herein, the electronic properties of 2D monolayer Ta2CS2 and its potential performance as 2D electrode candidate in Li+, Na+, K+, and Ca2+ ion batteries have been examined by utilizing first-principles calculations. The exfoliation of metallic monolayer Ta2CS2 is feasible owing to small cleavage energy of 0.64 J/m(2) and thermodynamical stability. The Ta2CS2-metal atom complexes are energetically favorable through examining adsorption energies. Furthermore, the low diffusion barriers of 0.21 eV for Li and 0.09 eV for Na and the high specific capacity of 367.23 mA h/g could be achieved. In particular, the low average open-circuit voltage of 0.45 V for Na implies 2D Ta2CS2 to be a suitable anode candidate in Na-ion batteries. These results provide fundamental insights for 2D Ta2CS2 in the field of energy conversion and storage.