First-principles study of the effect of O and S functional groups on the lithium storage properties of Zr₂N materials

As a novel two-dimensional nanomaterial, MXene is one of the most promising alternative electrode materials due to its large specific surface area, good electrical conductivity, excellent mechanical properties and tunable structure. This paper investigates the electrochemical performance of the MXene materials Zr2N and Zr2NS2 as anode materials for lithium and sodium ion batteries. The results showed that on the Zr2N monolayer, lithium and sodium ions tended to adsorb at the C site, while on the Zr2NS2 monolayer, lithium and sodium ions tended to adsorb at the B and A sites, respectively. The results of the Charge difference density diagram and Mulliken population analysis show that there is a significant electron transfer between the adsorbed metal ions and the material surface. This indicates that lithium and sodium ions form chemisorption on the Zr2N and Zr2NS2 surfaces. The high theoretical specific capacity and low migration barrier suggest that Zr2N and Zr2NS2 are promising anode materials for lithium and sodium ion batteries.