First-Principles Investigation of Transition Metal Dichalcogenide Nanotubes for Li and Mg Ion Battery Applications

First-principles calculations are employed to explore and rationalize the potentialities of MoS 2 and WS 2 armchair nanotubes for Li and Mg ion battery applications. A comparison with the reported values for Li insertion in TiS 2 and MoS 2 nanotubes shows that WS 2 and MoS 2 nanotubes presented enhanced ion mobility. Especially for MoS 2, the Li mobility is 4 times faster than in TiS 2 nanotubes. On the other hand, analysis of the Mg diffusion properties suggests that WS 2 nanotubes would be a better option, with ion mobility 3 times faster in relation to MoS 2 nanotubes. In terms of mobility, the Mg intercalation in WS 2 and MoS 2 nanotubes shows remarkable properties in comparison with Li insertion. Although it seems that Li and Mg insertion in WS 2 and MoS 2 nanotubes will be thermodynamically unstable, it is expected that the combination of nanotubes and high voltage electrode materials will increase the ion stability while keeping the faster ion mobility. Therefore, our results suggest high ion mobility at the surface of MoS 2 and WS 2 and support the potential application of the use of such systems as additive electrode materials for high-rate battery applications.