Construction of Hierarchical SnO<sub>2</sub>@NC@MoS<sub>2</sub>/C Nanotubes for Ultrastable Lithium- and Sodium-Ion Batteries
Bingqing Ye, Lei Xu, Wenbo Wu, Yuliang Ye, Zunxian Yang, Yinglin Qiu, Zhipeng Gong, Yuanqing Zhou, Qiaocan Huang, Zihong Shen, Zeqian Hong, Zongyi Meng, Zhiwei Zeng, Zhiming Cheng, Songwei Ye, Hongyi Hong, Qianting Lan, Fushan Li, Tailiang Guo, Sheng Xu
Abstract
In this work, a novel hierarchical tubular structure (SnO2@NC@MoS2/C) has been designed and synthesized using MnOx nanowires as a sacrificing template for the hollow tube and successively wrapping a SnO2 layer, nitrogen-doped carbon (NC) layer, and ultrathin MoS2 nanosheets incorporating into a carbon layer. In such a particular structure, the conductivity of SnO2 and MoS2 has 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 the spacing between MoS2 layers caused by the outermost carbon derived from glucose, the shuttling of Li+/Na+ between the layers becomes easier. Thanks to the advantages mentioned above, hierarchical hollow nanostructures feature the synergistic effects of different components, the SnO2@NC@MoS2/C nanocomposite displays an exceptional discharge capacity (980.9 mAh g–1 at 0.2 Ag–1) and long cycle stability (750 mAh g–1 at 1 Ag–1 for 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–1 after 500 cycles, respectively, which delivers an ultrastable high-rate cycle performance. Meanwhile, it also achieves eminent capacity (479.3 mAh g–1 at 0.2 Ag–1 over 150 cycles), small capacity attenuation 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, and 348.2 mAh g–1 at 0.1, 0.2, 0.5, 1, 2, and 5 Ag–1, respectively) when the composite used for sodium-ion batteries.