Amorphous Iron Oxyhydroxide Nanosheets: Synthesis, Li Storage, and Conversion Reaction Kinetics

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• 作者：Chen Xu ; Yi Zeng ; Xianhong Rui ; Jixin Zhu ; Huiteng Tan ; Antonio Guerrero ; Juan Toribio ; Juan Bisquert ; Germ脿 Garcia-Belmonte ; Qingyu Yan
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：August 29, 2013
• 年：2013
• 卷：117
• 期：34
• 页码：17462-17469
• 全文大小：396K
• 年卷期：v.117,no.34(August 29, 2013)
• ISSN：1932-7455

文摘

We present a facile approach to synthesize amorphous iron oxyhydroxide nanosheet from the surfactant-assisted oxidation of iron sulfide nanosheet. The amorphous iron oxyhydroxide nanosheet is porous and has a high surface area of 223 m² g^鈥?. The lithium storage properties of the amorphous iron oxyhydroxide are characterized: it is a conversion-reaction electrode material, and it demonstrates superior rate capabilities (e.g., discharge capacities as high as 642 mAh g^鈥? are delivered at a current density of 2 C). The impedance spectroscopy analysis identifies a RC series subcircuit originated by the conversion-reaction process. Investigation of the conversion-reaction kinetics through the RC subcircuit time constant reproduces the hysteresis in the discharge/charge voltage profile. Hysteresis is then connected to underlying thermodynamics of the conversion reaction rather than to a kinetic limitation.