Chemically Bonded TiO2-Bronze Nanosheet/Reduced Graphene Oxide Hybrid for High-Power Lithium Ion Batteries
Chemically Bonded TiO2-Bronze Nanosheet/Reduced Graphene Oxide Hybrid for High-Power Lithium Ion Batteries
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DOI：
10.1021/nn405534r
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发表时间：
2014-02-01
期刊：
影响因子：
17.1
通讯作者：
Bartlett, Bart M.
中科院分区：
文献类型：
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作者：
Etacheri, Vinodkumar;Yourey, Joseph E.;Bartlett, Bart M.
尽管锂离子电池由于其较高的能量密度而吸引了极大的兴趣，但缺乏高倍率性能电极材料和固有安全问题挑战了其商业应用。在此，我们展示了一种简单的光催化还原方法，该方法通过Ti 3 +-C键同时将氧化石墨烯（GO）和锚定（010）-多面介孔青铜相二氧化钛（TiO 2-B）纳米片还原为还原的氧化石墨烯（RGO）。利用电子顺磁共振（EPR）和X射线光电子能谱（XPS）技术研究了Ti 3 +-C键在光催化还原过程中的形成。当在1-3 V（相对于Li+/0）之间循环时，这些化学键合的TiO 2-B/RGO混合纳米结构与裸TiO 2-B纳米片和物理混合的TiO 2-B/RGO复合材料相比显示出显著更高的Li离子存储容量和倍率性能。此外，即使在40 ℃的高倍率下进行1000次充放电循环后，仍保留了80%的初始比（重量）容量。TiO 2-B/RGO纳米结构的电化学性能改善归因于暴露的（010）面、中孔性以及RGO单层和TiO 2-B纳米片之间的有效界面电荷转移。
Although Li-ion batteries have attracted significant interest due to their higher energy density, lack of high rate performance electrode materials and intrinsic safety issues challenge their commercial applications. Herein, we demonstrate a simple photocatalytic reduction method that simultaneously reduces graphene oxide (GO) and anchors (010)-faceted mesoporous bronze-phase titania (TiO2-B) nanosheets to reduced graphene oxide (RGO) through Ti3+-C bonds. Formation of Ti3+-C bonds during the photocatalytic reduction process was identified using electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) techniques. When cycled between 1-3 V (vs Li+/0), these chemically bonded TiO2-B/RGO hybrid nanostructures show significantly higher Li-ion storage capacities and rate capability compared to bare TiO2-B nanosheets and a physically mixed TiO2-B/RGO composite. In addition, 80% of the initial specific (gravimetric) capacity was retained even after 1000 charge-discharge cycles at a high rate of 40C The improved electrochemical performance of TiO2-B/RGO nanoarchitectures is attributed to the presence of exposed (010) facets, mesoporosity, and efficient interfacial charge transfer between RGO monolayers and TiO2-B nanosheets.