Theoretical prediction of the structural, electronic, mobility, and dynamic properties of Mo3N2T2 (T = H, O and OH) with Li adsorption feature

Two-dimensional (2D) MXenes are attracting increasing interest as electrode materials for lithium ion batteries (LIBs), because lithium ions can diffuse in a 2D lattice surface. The electronic structure, electron and ion motion dynamics, and structural stability upon lithiation and delithiation on the bare, H-, O-, and OH-terminated Mo3N2 MXene were intensively investigated using the DFT method. The theoretical results revealed that Mo3N2 and Mo3N2O2 have excellent absorption and stability for lithium-ion storage. There is no band gap at the traditional Fermi level (0/eV) at any configuration, which means it has excellent electronic conductivity. The extended orbital could enhance the exchange interaction between Mo 4d and N 2p for terminated atoms, leading to an asymmetric charge distribution in Mo-N and Mo T (T = H, O and OH) bonds. The adsorption of Li ions on Mo3N2O2 layers indicates that the O-terminated moiety can obviously improve the diffusion of Li ions. The stability was studied by ab initio molecular dynamics (AIMD) simulation at a series of temperatures. The lithium ions have a gradual evolution of thermal motions with increasing temperature. These results suggest that Mo3N2 and Mo3N2O2 can be a promising electrode material for lithium-ion batteries in terms of Mo3N2O2 specific capacity, diffusion dynamics, and structural stability.