Multi-role TiO₂ layer coated carbon@few-layered MoS₂ nanotubes for durable lithium storage

The combination of transitional-metal dichalcogenides with rigid TiO₂ has been proved to be an effective strategy to improve their structural stability but the poor long-term cycling stability at high current density still hinders their practical applications. In this paper, a smart structure consisting of multi-role TiO₂ coated on carbon@few-layered MoS₂ (CMT) nanotubes was synthesized to achieve superior long-term cycling performance. In this unique structure, the anatase/rutile TiO₂ is explored as a coating layer of MoS₂, which not only accommodates the volume change resulting from the phase transformation from S to Li₂S but also alleviates the “shuttle effect” caused by the dissolution of long-chain lithium polysulfides. Moreover, the carbon nanotubes serve as a conductive backbone for MoS₂ to improve the electron transport ability of electrode and the few-layered MoS₂ nanosheets with expanded interlayers can shorten the lithium-ion pathway and improve the lithium-ion diffusion mobility. Benefitting from the synergetic effects of TiO₂ layer, carbon and MoS₂, when applied as anode of LIBs, the CMT demonstrates an extraordinary long-term cycling performance (528.5 mAh g⁻¹ at 1000 mA g⁻¹ and 455.2 mAh g⁻¹ at 2000 mA g⁻¹ after 1000 cycles), which outperforms most of the MoS₂-TiO₂ based anode materials reported before. This work should offer new perspectives into exploring high-performance MoS₂-TiO₂ based anode materials for efficient lithium storage.