Effect of chemical oxidation for nano-size γ-Fe2O3 as lithium battery cathode
Effect of chemical oxidation for nano-size γ-Fe2O3 as lithium battery cathode
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纳米γ-Fe2O3作为锂电池正极的化学氧化效果
DOI：
10.1016/j.jpowsour.2006.12.001
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发表时间：
2007
影响因子：
9.2
通讯作者：
R. Kanno
中科院分区：
文献类型：
--
作者：
Sho Kanzaki;A. Yamada;R. Kanno
为提高纳米晶γ-Fe2O_3在锂电池中的电化学性能，对其进行了表面处理。TG测试和FT-IR光谱表明，NO2BF4化学氧化去除了表面的残留物，改善了充放电性能，获得了更高的容量和更好的可逆性。用X射线衍射仪和穆斯堡尔谱研究了其充放电机理。纳米γ-Fe2O_3的可逆充放电反应是通过尖晶石和无序岩盐型之间的相变进行的，这一相变被认为是块体材料的不可逆过程。讨论了相变的纳米效应和充放电机理。
Surface treatment of nano-crystalline γ-Fe2O3was examined to improve its electrochemical performances for lithium battery. Removal of residual phases on the surface by chemical oxidation with NO2BF4was confirmed by TG measurement and FT-IR spectroscopy, and the process improved charge–discharge characteristics; higher capacity and better reversibility were obtained. The charge–discharge mechanism was studied by X-ray diffraction measurement and Mössbauer spectroscopy. The reversible charge–discharge reaction of the nano-size γ-Fe2O3was proceeded by a phase transition between the spinel and the disordered rock-salt type, which was previously claimed to be an irreversible process for the bulk materials. The nano-size effect of the phase transitions and the charge–discharge mechanism will be discussed.