Construction of Hierarchical SnO2@NC@MoS2/C Nanotubes for Ultrastable Lithium- and Sodium-Ion Batteries

In this work, a novel hierarchical tubular structure (SnO2@NC@MoS2/C) has been designed and synthesized using MnOxnanowires as a sacrificing template forthe hollow tube and successively wrapping a SnO2layer, nitrogen-doped carbon (NC)layer, and ultrathin MoS2nanosheets incorporating into a carbon layer. In such aparticular structure, the conductivity of SnO2and MoS2has been obviously improved,and the large volume change caused by the lithium/sodium-ion (Li+/Na+) intercalation/deintercalation has also been effectively alleviated. Especially, due to the expansion of thespacing between MoS2layers caused by the outermost carbon derived from glucose, theshuttling of Li+/Na+between the layers becomes easier. Thanks to the advantagesmentioned above, hierarchical hollow nanostructures feature the synergistic effects ofdifferent components, the SnO2@NC@MoS2/C nanocomposite displays an exceptionaldischarge capacity (980.9 mAh g-1at 0.2 Ag-1) and long cycle stability (750 mAh g-1at1Ag-1for 450 cycles) when applied in lithium-ion batteries. Even at 2, 5, and 10 Ag-1,the specific capacities still reach up to 672.7, 630.1, and 565 mAh g-1after 500 cycles, respectively, which delivers an ultrastable high-rate cycle performance. Meanwhile, it also achieves eminent capacity (479.3 mAh g-1at 0.2 Ag-1over 150 cycles), small capacityattenuation rate (0.06% per cycle after 2000 cycles at 1 Ag-1), and superior rate capacity (818.5, 691.6, 577.6, 506.3, 442.4, and348.2 mAh g-1at 0.1, 0.2, 0.5, 1, 2, and 5 Ag-1, respectively) when the composite used for sodium-ion batteries