Revisiting on the effect and role of TiO2 layer thickness on SnO2 for enhanced electrochemical performance for lithium-ion batteries
Revisiting on the effect and role of TiO2 layer thickness on SnO2 for enhanced electrochemical performance for lithium-ion batteries
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DOI：
10.1016/j.electacta.2017.11.166
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发表时间：
2017-12
影响因子：
6.6
通讯作者：
J. Cheong;Joon Ha Chang;Chanhoon Kim;F. J. Mweta;Ji-Won Jung;J. Y. Lee;Il‐Doo Kim
中科院分区：
文献类型：
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作者：
J. Cheong;Joon Ha Chang;Chanhoon Kim;F. J. Mweta;Ji-Won Jung;J. Y. Lee;Il‐Doo Kim
电极材料的表面和界面性质的仔细调制是决定整体电化学特性的关键因素。最近的研究表明，金属氧化物阳极（如氧化锡（IV）（SnO 2））上的金属氧化物纳米涂层（如氧化钛（IV）（TiO 2））表现出上级的电化学性能，但对TiO 2层厚度的影响和作用的基础研究有限。在这里，我们已经成功地进行了深入的研究，如何在SnO 2上的TiO 2覆盖层的厚度可以有显着的影响，在电化学的整体参数。结果表明，12 nm的TiO 2覆盖层即使在80次循环后也显示出良好的循环保持率（75.8%），并且即使在高电流密度（5000 mA g-1）下也保持438.3 mAh g-1的容量。令人惊讶的是，进一步发现，与SnO 2相比，TiO 2层不仅抑制了体积膨胀，而且有助于促进Li离子的传输。TiO 2层的离子和导电性的改善是更好的循环保持和倍率性能的主要因素。最后，采用透射电镜原位分析了TiO2@SnO2纳米管上固体电解质界面层的生长动力学，结果表明，与SnO 2纳米管相比，TiO 2纳米管上的界面层均匀且较薄.
Careful modulation of surficial and interfacial properties of electrode materials is a critical factor for determining overall electrochemical characteristics. Recent studies have indicated that metal oxide nanocoating layer (such as titanium (IV) oxide (TiO2)) on metal oxide anodes (such as tin (IV) oxide (SnO2)) exhibited superior electrochemical properties, but fundamental research on the effect and role of TiO2layer thickness has been limited. Here we have successfully conducted in-depth study on how the thickness of TiO2overlayer on SnO2can have significant influence in the overall parameters of electrochemistry. It is revealed that TiO2overlayer with 12 nm shows good cycle retention (75.8%) even after 80 cycles and retains capacity of 438.3 mAh g−1even at high current density (5000 mA g−1). Surprisingly, it was further discovered that TiO2layer not only alleviates the volume expansion but also helps to facilitate Li ion transport compared with SnO2. The improvements in both ionic and electrical conductivity of TiO2layer are main factors in better cycle retention and rate capabilities. Finally,in situtransmission electron microscopy analysis was adopted to observe the growth dynamics of solid electrolyte interphase layer on TiO2@SnO2, which demonstrates that TiO2overlayer results in homogeneous and thinner interphase layer compared with SnO2NTs.