Porosity-Controlled TiNb2O7 Microspheres with Partial Nitridation as A Practical Negative Electrode for High-Power Lithium-Ion Batteries
Porosity-Controlled TiNb2O7 Microspheres with Partial Nitridation as A Practical Negative Electrode for High-Power Lithium-Ion Batteries
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DOI：
10.1002/aenm.201401945
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发表时间：
2015-04-22
影响因子：
27.8
通讯作者：
Paik, Ungyu
中科院分区：
文献类型：
--
作者：
Park, Hyunjung;Wu, Hao Bin;Paik, Ungyu
钛铌氧化物(TiNb2O7)因其高倍率工作的潜力、更高的安全性和387mAHg(-1)的理论容量而被公认为是一种很有前途的锂离子电池负极材料。然而，由于它的宽禁带能(E-g>；2 eV)，它的锂离子扩散性差，电子导电性低。本文通过简单的溶剂热反应制备了多孔TiNb2O7微球(PtNO MSS)。PTNO分子筛的颗粒尺寸约为1.2微米，孔径在5-35 nm之间可控。对PtNO MSS进行氨气氮化处理，在表面引入导电Ti1-xNbxN层，形成氮化PtNO(NPTNO)MSS。多孔结构和导电Ti1-xNbxN层增强了与Li+离子和电子相关的输运动力学，从而显著提高了电化学性能。结果表明，NPTNO电极具有约265mAHg(-1)的高放电容量、卓越的倍率性能(100C时约为143mAg-1)和持久的长期循环性能(5C下1000次循环的容量保持率约为91%)。这些结果显示了TiNb2O7作为一种实用的高倍率锂离子电池负极材料的巨大潜力。
Titanium niobium oxide (TiNb2O7) has been recognized as a promising anode material for lithium-ion batteries (LIBs) in view of its potential to operate at high rates with improved safety and high theoretical capacity of 387 mAh g(-1). However, it suffers from poor Li+ ion diffusivity and low electronic conductivity originated from its wide band gap energy (E-g > 2 eV). Here, porous TiNb2O7 microspheres (PTNO MSs) are prepared via a facile solvothermal reaction. PTNO MSs have a particle size of approximate to 1.2 mu m and controllable pore sizes in the range of 5-35 nm. Ammonia gas nitridation treatment is conducted on PTNO MSs to introduce conducting Ti1-xNbxN layer on the surface and form nitridated PTNO (NPTNO) MSs. The porous structure and conducting Ti1-xNbxN layer enhance the transport kinetics associated with Li+ ions and electrons, which leads to significant improvement in electrochemical performance. As a result, the NPTNO electrode shows a high discharge capacity of approximate to 265 mAh g(-1), remarkable rate capability (approximate to 143 mAh g(-1) at 100 C) and durable long-term cyclability (approximate to 91% capacity retention over 1000 cycles at 5 C). These results demonstrate the great potential of TiNb2O7 as a practical high-rate anode material for LIBs.