First-principle prediction of Penta-NiN2 monolayer as electrode materials for Na and K ion batteries

Abstract

The atomic configurations, structural stability, and electrochemical performances of the pentagonal NiN2 (penta-NiN2) monolayer were investigated as an electrode material via density functional theory (DFT) methods. The results reveal that the penta-NiN2 exhibits intrinsic semiconductor characteristics and dynamic stability. The tiny inherent diffusion energy (<0.10 eV), low average open-circuit voltage (OCV) of 0.05–0.25 V and high storage capacity of 1854.67 mA h g−1 and 618.22 mA h g−1 indicate that the penta-NiN2 is prefer to be an anode material for Na/K. This study demonstrates that the 2D penta-NiN2 is highly suitable as an anode material for Na/K batteries.