First‑principles study of electronic structure, sodium diffusion on 2D TiO 2 monolayers for sodium-ion battery electrodes.

The search for suitable electrode materials is crucial for the development of high-performance Na-ion batteries (NIBs). In recent years, significant attention has been drawn to two-dimensional (2D) oxides as potential NIB electrode materials. In this study, employing the first-principles density functional theory method, we investigate the thermodynamic and kinetic properties of Na adsorption and diffusion behavior on the 2D TiO 2 (010) monolayer. Our findings demonstrate that the 2D anatase TiO 2 (010) monolayer exhibits enhanced thermodynamic stability. Furthermore, the Na atoms preferentially adsorb on the top of oxygen atoms within the TiO 2 (010) monolayer, and their diffusion along the [100] direction is characterized by a low energy barrier of 0.054 eV. This comprehensive analysis sheds light on the structural stability, preferred adsorption sites, and diffusion paths of Na atoms on the 2D anatase TiO 2 (010) monolayer, providing valuable insights into the nature of the material's structure and Na ion transport. Moreover, the 2D structure of the TiO 2 matrix facilitates short Na diffusion lengths and a large electrode/electrolyte interface, thereby demonstrating the potential of this material as an NIB electrode material.