ALD TiO2-Coated Flower-like MoS2 Nanosheets on Carbon Cloth as Sodium Ion Battery Anode with Enhanced Cycling Stability and Rate Capability.
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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DOI：
10.1021/acsami.6b13179
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发表时间：
2017-01
影响因子：
9.5
通讯作者：
Weina Ren;Weiwei Zhou;Haifeng Zhang;Chuanwei Cheng
中科院分区：
文献类型：
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作者：
Weina Ren;Weiwei Zhou;Haifeng Zhang;Chuanwei Cheng
我们报道了在碳布上制备三维花状二硫化钼纳米片阵列作为钠离子电池的无粘结剂阳极。采用原子层沉积法在MoS 2表面制备了超薄共形的TiO 2层。电化学性能测试表明，原子层沉积TiO 2层可以提高MoS 2的循环稳定性和倍率性能。具有0.5-nm TiO 2涂层电极的MoS 2纳米片在200 mA g-1下显示出最高的1392 mA h g-1的初始放电容量，与裸MoS 2相比增加了53%。经过150次循环后，在200 mA h g-1下，TiO 2包覆的MoS 2的容量留存率达到其第二次循环容量的75.8%，而纯MoS 2的容量保持率为59%。通过SEM、XRD、EIS等表征手段，进一步揭示了MoS 2电极表面改性的机理，证实了改性后MoS 2电极的结构退化和SEI膜的形成得到了有效的抑制。
We report the fabrication of 3D flower-like MoS2 nanosheets arrays on carbon cloth as a binder-free anode for sodium ion battery. Ultrathin and conformal TiO2 layers are used to modify the surface of MoS2 by atomic layer deposition. The electrochemical performance measurements demonstrate that the ALD TiO2 layer can improve the cycling stability and rate capability of MoS2. The MoS2 nanosheets with 0.5-nm TiO2 coating electrode show the highest initial discharge capacity of 1392 mA h g-1 at 200 mA g-1, which is increased by 53% compared with that of bare MoS2. After 150 cycles, the capacity retention rate of the TiO2-coated MoS2 achieves 75.8% of its second cycle's capacity at 200 mA h g-1 in contrast to that of 59% of pure MoS2. 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 TiO2 modifications can prevent the structural degradation and the formation of SEI film of MoS2 electrode.