Aligned TiO2 nanotube/nanoparticle heterostructures with enhanced electrochemical performance as three-dimensional anode for lithium-ion microbatteries
Aligned TiO2 nanotube/nanoparticle heterostructures with enhanced electrochemical performance as three-dimensional anode for lithium-ion microbatteries
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DOI：
10.1088/0957-4484/25/45/455401
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发表时间：
2014-11
期刊：
影响因子：
3.5
通讯作者：
Ke-yu Xie;Min Guo;W. Lu;Haitao Huang
中科院分区：
文献类型：
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作者：
Ke-yu Xie;Min Guo;W. Lu;Haitao Huang
通过简单地将阳极氧化后的二氧化钛纳米管浸入水中，并通过后退火使其进一步结晶，开发出一种具有对齐的二氧化钛纳米管/纳米颗粒异质结构（TiO₂NTs/NPs）的新型二氧化钛三维（3D）阳极。通过场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）证实了这种异质结构，其核心为管状形态，内外表面均由纳米颗粒组成。对于TiO₂NTs/NPs异质结构电极，在50次循环后保持了0.126 mAh·cm⁻²的可逆面积容量，这高于TiO₂NTs电极（50次循环后为0.102 mAh·cm⁻²）。在电流密度为0.02、0.04、0.06、0.08、0.10和0.20 mA·cm⁻²时，TiO₂NTs/NPs异质结构电极的面积容量分别为0.142、0.127、0.117、0.110、0.104和0.089 mAh·cm⁻²，而TiO₂NTs电极的面积容量分别为0.123、0.112、0.105、0.101、0.094和0.083 mAh·cm⁻²。电化学性能的提高归因于TiO₂NTs/NPs异质结构电极独特的微观结构，其中TiO₂NT核心用作电子传输的直通道，而TiO₂NP为锂离子的嵌入/脱出提供了更大的表面积。此处描述的结果启发了一种简便的方法来制造具有增强电化学性能的三维阳极，用于锂离子微电池应用。
A novel TiO2 three-dimensional (3D) anode with an aligned TiO2 nanotube/nanoparticle heterostructure (TiO2 NTs/NPs) is developed by simply immersing as-anodized TiO2 NTs into water and further crystallizing the TiO2 NTs by post-annealing. The heterostructure, with its core in a tubular morphology and with both the outer and inner surface consisting of nanoparticles, is confirmed by FESEM and TEM. A reversible areal capacity of 0.126 mAh · cm−2 is retained after 50 cycles for the TiO2 NTs/NPs heterostructure electrode, which is higher than that of the TiO2 NTs electrode (0.102 mAh · cm−2 after 50 cycles). At the current densities of 0.02, 0.04, 0.06, 0.08, 0.10 and 0.20 mA · cm−2, the areal capacities are 0.142, 0.127, 0.117, 0.110, 0.104 and 0.089 mAh · cm−2, respectively, for the TiO2 NTs/NPs heterostructure electrode compared to the areal capacities of 0.123, 0.112, 0.105, 0.101, 0.094 and 0.083 mAh · cm−2, respectively, for the the TiO2 NTs electrode. The enhanced electrochemical performance is attributed to the unique microstructure of the TiO2 NTs/NPs heterostructure electrode with the TiO2 NT core used as a straight pathway for electronic transport and with TiO2 NP offering enhanced surface areas for facile Li+ insertion/extraction. The results described here inspire a facile approach to fabricate a 3D anode with an enhanced electrochemical performance for lithium-ion microbattery applications.