Electrochemical Insertion of Li and Na Ions into Nanocrystalline Fe3O4 and α-Fe2O3 for Rechargeable Batteries
Electrochemical Insertion of Li and Na Ions into Nanocrystalline Fe3O4 and α-Fe2O3 for Rechargeable Batteries
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DOI：
10.1149/1.3254160
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发表时间：
2010-01-01
影响因子：
3.9
通讯作者：
Yamada, Yasuhiro
中科院分区：
文献类型：
--
作者：
Komaba, Shinichi;Mikumo, Takashi;Yamada, Yasuhiro
制备了平均粒径为400、100和10 nm的Fe3O4粉末，并用x射线衍射、透射电镜、穆斯堡尔光谱和电化学方法对其进行了表征。为了研究Fe3O4的电化学活性与粒径效应的关系，在含锂离子或钠离子的非质子电解质中进行了恒流循环试验。随着平均粒径的减小，电化学活性显著增强。沉淀法制备的纳米晶Fe3O4 （10 nm）在含锂离子的电解液中，在2 ~ 3 V电压范围内的可充电容量为190 mA h g(-1)，而400 nm和100 nm Fe3O4粉末的可充电容量分别为10和80 mA h g（-1）。电化学循环后样品的非原位x射线衍射研究表明，铁离子从四面体位置部分可逆地迁移到八面体位置，并保留尖晶石框架结构。纳米晶Fe3O4和α - fe2o3在钠盐电解质中具有较高的电化学活性。纳米晶Fe3O4和α - fe2o3的可充电容量分别为160和170 mA h g(-1)，且容量保持良好。(C) 2009电化学学会。[DOI: 10.1149/1.3254160]版权所有。
Fe3O4 powders with different particle sizes on average (400, 100, and 10 nm) were prepared and characterized by X-ray diffraction, transmission electron microscopy, Mossbauer spectroscopy, and electrochemical methods. To examine the electrochemical activity of Fe3O4 in relation to the particle size effect, galvanostatic cycling tests in aprotic electrolytes containing lithium or sodium ions were conducted. The electrochemical activity was significantly enhanced as the mean particle size decreased. The nanocrystallized Fe3O4 (10 nm) prepared by precipitation method delivered 190 mA h g(-1) of the rechargeable capacity in the voltage range of 2-3 V in a lithium-ion containing electrolyte, whereas the 400 and 100 nm Fe3O4 powders showed 10 and 80 mA h g(-1) of the rechargeable capacity, respectively. An ex situ X-ray diffraction study for the electrochemically cycled samples suggested the partly reversible Fe ion migration from the tetrahedral sites to the octahedral sites with a retained spinel framework structure. The nanocrystallized Fe3O4 as well as alpha-Fe2O3 were highly electrochemically active in the sodium salt electrolyte. The rechargeable capacity of 160 or 170 mA h g(-1) with excellent capacity retention was obtained for nanocrystalline Fe3O4 or alpha-Fe2O3, respectively. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3254160] All rights reserved.