Enhanced Alkali-Ion Adsorption in Strongly Bonded Two-Dimensional TiS2/MoS2 van der Waals Heterostructures

Despite their remarkable properties, many two-dimensional (2D) materials do not possess the desired characteristics to enhance the energy density, rate performance, and cycle life of batteries when used as standalone materials for battery electrodes. However, engineering 2D van der Waals (vdW) heterostructures by stacking different 2D materials offers new opportunities for battery electrodes, combining desirable features and overcoming the limitations of the constituent 2D layers. In this work, using first-principles calculations, we investigated the electronic structure, thermal stability, stress–strain response, alkali (Li/Na/K)-ion adsorption, and diffusion characteristics of 2D heterostructures of titanium disulfide (TiS2) and molybdenum disulfide (MoS2) monolayers with attractive applications in alkali-metal ion batteries (AMIBs). This work revealed relatively strong interlayer interactions in the heterostructure, resulting in significant enhancements in the adsorption of alkali ions compared to the respective monolayers. This work demonstrates that TiS2/MoS2 heterostructures offer excellent mechanical flexibility, increased strength, and greater strain endurance. The results indicate that TiS2/MoS2 heterostructures are promising materials for next-generation flexible anodes for AMIBs.