ALD TiO2-Coated Flower-like MoS2 Nanosheets on Carbon Cloth as Sodium Ion Battery Anode with Enhanced Cycling Stability and Rate Capability

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• 作者：Weina Ren ; Weiwei Zhou ; Haifeng Zhang ; Chuanwei Cheng
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：9
• 期：1
• 页码：487-495
• 全文大小：767K
• ISSN：1944-8252

文摘

We report the fabrication of 3D flower-like MoS<sub>2sub> nanosheets arrays on carbon cloth as a binder-free anode for sodium ion battery. Ultrathin and conformal TiO<sub>2sub> layers are used to modify the surface of MoS<sub>2sub> by atomic layer deposition. The electrochemical performance measurements demonstrate that the ALD TiO<sub>2sub> layer can improve the cycling stability and rate capability of MoS<sub>2sub>. The MoS<sub>2sub> nanosheets with 0.5-nm TiO<sub>2sub> coating electrode show the highest initial discharge capacity of 1392 mA h g<sup>–1sup> at 200 mA g<sup>–1sup>, which is increased by 53% compared with that of bare MoS<sub>2sub>. After 150 cycles, the capacity retention rate of the TiO<sub>2sub>-coated MoS<sub>2sub> achieves 75.8% of its second cycle’s capacity at 200 mA h g<sup>–1sup> in contrast to that of 59% of pure MoS<sub>2sub>. Furthermore, the mechanism behind the experimental results is revealed by ex situ scanning electron microscope (SEM), X-ray powder diffraction (XRD), and electrochemical impedance spectroscopy (EIS) characterizations, which confirms that the ultrathin TiO<sub>2sub> modifications can prevent the structural degradation and the formation of SEI film of MoS<sub>2sub> electrode.