Lithium adsorption properties of two-dimensional chromium nitride

Two-dimensional (2D) materials promise improved performance and energy storage capacities in next-generation Li-ion batteries due to their large surface area, enhanced specific capacity, and quick ion diffusion coupled with light weight and flexibility. Two-dimensional CrN is a recently proposed novel 2D material showing interesting properties regarding ferromagnetism, optical transparency, and good elastic properties, as well as catalytic and gas sensing properties, in free-standing or heterostructure form combined with other 2D materials. This study examines the lithiation characteristics of 2D CrN sheets with density functional theory (DFT) calculations. Using Perdew–Burke–Ernzerhoff (PBE) DFT calculations with the Generalized Gradient Approximation (GGA), we computed the various parameters for Li adsorption on 2D CrN. We carried out structural optimization calculations with the Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm for the adsorption studies, and performed a climbing image nudged elastic band calculation to evaluate the diffusion barriers. In all calculations, the van der Waals forces were taken into consideration, with Grimme’s DFT-D3 correction scheme. In our studies, 2D CrN demonstrated an excellent theoretical specific capacity up to 1322.73mAhg-1, a small electrode potential of about 0.2V, and a diffusion barrier of 0.17eV. According to the calculations, 2D CrN might be used as a substitute anode material in Li-ion storage.