Electrochemical In Situ Formation of a Stable Ti-Based Skeleton for Improved Li-Storage Properties: A Case Study of Porous CoTiO3 Nanofibers
Electrochemical In Situ Formation of a Stable Ti-Based Skeleton for Improved Li-Storage Properties: A Case Study of Porous CoTiO3 Nanofibers
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电化学原位形成稳定的钛基骨架以改善储锂性能：多孔 CoTiO3 纳米纤维的案例研究
DOI：
10.1002/chem.201700984
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Wu Xing-Long
中科院分区：
文献类型：
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作者：
Liu Si-Yu;Fan Chao-Ying;Wang Han-Chi;Zhang Jing-Ping;Wu Xing-Long
与原始的单金属氧化物相比，双金属过渡金属氧化物具有优越的电化学性能，近年来已成为锂离子电池（LIBs）应用的重要研究课题。在此，我们报告了一种简单且可扩展的静电纺丝方法来合成多孔cotio3纳米纤维，作为电化学原位形成纳米结构双金属过渡金属氧化物的前驱体。这种策略确保了在锂化/去硫化过程中两种过渡金属氧化物的均匀混合和完美接触。此外，基于超细cotio3纳米晶体的cotio3纳米纤维相互连接形成纳米/微结构3D网络，确保了由双金属过渡金属氧化物组成的原位形成结构的高稳定性，以及离子/电子的快速转移和电解质进入电极的渗透。电化学测量表明，CoO/ tio2电极具有优异的锂存储性能（647 mAh g−1at 0.1 Ag−1）和保持性能（600 mAh g−1at 1ag−1,1200次循环后）。此外，通过非原位X射线光电光谱和循环伏安法对电化学反应机理进行了探讨，证实了电极中的两相反应过程。这些结果清楚地验证了cotio3的潜力，它具有独特的纳米/微结构形态，可以作为双金属过渡金属氧化物的前驱体，用作长寿命锂离子电池的阳极材料。
Bimetallic transition‐metal oxides, which exhibit superior electrochemical properties compared with pristine single‐metal oxides, have recently become a topic of significant research interest for applications in lithium‐ion batteries (LIBs). Herein, we report a simple and scalable electrospinning method to synthesize porous CoTiO3nanofibers as the precursor for nanostructured bimetallic transition‐metal oxides formed electrochemically in situ. This strategy ensures uniform mixing and perfect contact between two constituent transition‐metal oxides during the lithiation/delithiation process. Furthermore, CoTiO3nanofibers based on ultrafine CoTiO3nanocrystals are interconnected to form a nano/microstructured 3D network, which ensures the high stability of the in situ formed structure composed of bimetallic transition‐metal oxides, and also fast ion/electron transfer and electrolyte penetration into the electrode. Electrochemical measurements revealed the excellent lithium storage (647 mAh g−1at 0.1 Ag−1) and retention properties (600 mAh g−1at 1 Ag−1after 1200 cycles) of the CoO/TiO2electrode. Moreover, the electrochemical reaction mechanism was explored by using ex situ X‐ray photoelectric spectroscopy and cyclic voltammetry tests, which confirmed the two‐phase reaction processes in the electrodes. These results clearly validate the potential of CoTiO3with a unique nano/microstructured morphology as the precursor for a bimetallic transition‐metal oxide for use as the anode material for long‐life LIBs.