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 MoS2 and WS2 armchair nanotubes for Li and Mg ion battery applications. A comparison with the reported values for Li insertion in TiS2 and MoS2 nanotubes shows that WS2 and MoS2 nanotubes presented enhanced ion mobility. Especially for MoS2, the Li mobility is 4 times faster than in TiS2 nanotubes. On the other hand, analysis of the Mg diffusion properties suggests that WS2 nanotubes would be a better option, with ion mobility 3 times faster in relation to MoS2 nanotubes. In terms of mobility, the Mg intercalation in WS2 and MoS2 nanotubes shows remarkable properties in comparison with Li insertion. Although it seems that Li and Mg insertion in WS2 and MoS2 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 MoS2 and WS2 and support the potential application of the use of such systems as additive electrode materials for high-rate battery applications.