Two-dimensional MnC as a potential anode material for Na/K-ion batteries: a theoretical study.

Sodium (Na)-ion batteries (NIBs) and potassium (K)-ion batteries (KIBs) have grabbed great attention because they are cheaper, more abundant in earth, and safer alternatives of lithium-ion batteries. However, the lack of anode materials for NIBs/KIBs with good performance has been the main obstacle. In this paper, we studied monolayer MnC by carrying out calculations on the basis of first principle study to see if it can be a potential anode material for NIBs and KIBs. Calculation results show that monolayer MnC processes good negative adsorption energies of - 2.83 eV for Na and - 2.16 eV for K. Moreover, MnC has comparable theoretical capacities for Na and K of 475 mAh/g and 253 mAh/g, respectively. Our calculation results manifest that the MnC can be a promising anode material for NIBs. MnC monolayer absorbed with two layers of Na atoms.