First-principles calculation on the lithium storage properties of high-entropy MXene TiC(NOFS)

Experimental studies had shown that a variety of surface functional groups exist simultaneously on the surface of Ti 3 C 2 T x MXenes. However, current theoretical calculations on MXenes, used as anode materials for lithium-ion batteries, consider only one surface functional group, which fails to take into account the actual situation. In this study, combining the characteristics of high-entropy materials and two-dimensional MXene material, a model of MXene with multiple surface functional groups was constructed, and its electrochemical performance as an anode material for lithium-ion batteries was further explored. The Ti 3 C 2 (N 0.25 O 0.25 F 0.25 S 0.25 ) 2 monolayer exhibited metallic properties. Meanwhile, Li atoms could be stably adsorbed on the surface and the diffusion energy barrier of Li on the surface was only 0.17 eV. First-principles calculation showed that Ti 3 C 2 (N 0.25 O 0.25 F 0.25 S 0.25 ) 2 monolayer had good rate performance and low open-circuit voltage (1 V), corresponding to a lithium storage capacity of 385.38 mA h g −1 . The results of our work might inspire further studies on the Li storage performance of high-entropy MXenes experimentally and theoretically. By first-principles calculation and comparison with other published MXenes, it is found that the diffusion energy barrier of high-entropy MXene is lower.