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• 作者：Hai Ming ; Jun Ming ; Seung-Min Oh ; Shu Tian ; Qun Zhou ; Hui Huang ; Yang-Kook Sun ; Junwei Zheng
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：September 10, 2014
• 年：2014
• 卷：6
• 期：17
• 页码：15499-15509
• 全文大小：957K
• ISSN：1944-8252

文摘

A simple surfactant-assisted reflux method was used in this study for the synthesis of cocklebur-shaped Fe₂O₃ nanoparticles (NPs). With this strategy, a series of nanostructured Fe₂O₃ NPs with a size distribution ranging from 20 to 120 nm and a tunable surface area were readily controlled by varying reflux temperature and the type of surfactant. Surfactants such as cetyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (F127) and sodium dodecyl benzenesulfonate (SDBS) were used to achieve large-scale synthesis of uniform Fe₂O₃ NPs with a relatively low cost. A new composite of Fe₃O₄@CF_x was prepared by coating the primary Fe₂O₃ NPs with a layer of F-doped carbon (CF_x) with a one-step carbonization process. The Fe₃O₄@CF_x composite was utilized as the anode in a lithium ion battery and exhibited a high reversible capacity of 900 mAh g^鈥? at a current density of 100 mA g^鈥? over 100 cycles with 95% capacity retention. In addition, a new Fe₃O₄@CF_x/LiNi_0.5Mn_1.5O₄ battery with a high energy density of 371 Wh kg^鈥? (vs cathode) was successfully assembled, and more than 300 cycles were easily completed with 66.8% capacity retention at 100 mA g^鈥?. Even cycled at the high temperature of 45 掳C, this full cell also exhibited a relatively high capacity of 91.6 mAh g^鈥? (vs cathode) at 100 mA g^鈥? and retained 54.6% of its reversible capacity over 50 cycles. Introducing CF_x chemicals to modify metal oxide anodes and/or any other cathode is of great interest for advanced energy storage and conversion devices.

Keywords:

nanoparticles; oxides; carbon; electrochemical properties; batteries