Structural and Electronic Properties of MO<sub>2</sub>/MS<sub>2</sub> Heterojunctions and Potential Application in Lithium-Ion Batteries
Dongyang Zhu, Qiuyu Zhang, Xiaowei Li, Yihe Zhang
Abstract
Transition-metal chalcogenides (TMDs) are excellent lithium-ion battery electrode materials with high efficiency, high stability, and superior electrical conductivity. In this work, heterojunctions were constructed by tensile strained MO2 (M = Mo, W) and compressive strained MS2 (M = Mo, W), and the electronic property, adsorption, and diffusion of Li in the interlayer of heterojunctions were calculated by using the first-principles calculations. The results show that the band gaps of heterojunctions are very small in virtue of strain and van der Waals interaction. The calculated adsorption energy of Li is from −1.374 to −2.342 eV demonstrating Li can be adsorbed spontaneously without cluster. Furthermore, the diffusion barriers of Li in heterojunctions are in the range of 0.16–0.21 eV which are lower than that on the surface of single layer. The lower diffusion barrier and narrower band gap have made heterojunctions a good charge and discharge performance as an electrode material. Our results may be a reference for the MX2 (M = Mo, W; X = O, S) heterojunctions used as electrode materials of lithium-ion batteries in experiments.