Low-crystallinity molybdenum sulfide nanosheets assembled on carbon nanotubes for long-life lithium storage: Unusual electrochemical behaviors and ascending capacities

Abstract Low-crystallinity molybdenum sulfide (LCMS, Mo:S = 1:2.75) nanosheets synthesized by a facile and low temperature solvothermal method is now reported. The as-prepared LCMS anode material is composited of MoS 2 layers mixed with amorphous MoS 3 , which leads to an unusual electrochemical process for lithium storage compared to typical MoS 2 anode. The existence of MoS 3 and Mo (VI) provide strong adsorption and binding sites for polar polysulphides, which compels abundant sulfur to turn into new-formed MoS 3 rather than diffuse into electrolyte. To fully utilize this novel electrochemical process, LCMS is decorated on carbon nanotubes, obtaining well-dispersed CNTs@LCMS. As electrode material for lithium storage, CNTs@LCMS exhibits a noticable ascending trend in capacity from 820 mA h g −1 to 1350 mA h g −1 at 100 mA g −1 during 130 cycles. The persistent ascending capacity is ascribed to the increasing lithium storage caused by new-formed MoS 3 , combined with the reduced volume change benifiting from well-dispersed CNTs@LCMS. Furthermore, the ascending performance is proved to be able to effectively extend the circulation life (up to 200%) for lithium-ion batteries by mathematical modeling and calculation. Accordingly, the CNTs@LCMS composite is a promising anode material for long-life lithium-ion batteries.