Graphene encapsulated Fe3O4 nanorods assembled into a mesoporous hybrid composite used as a high-performance lithium-ion battery anode material
Graphene encapsulated Fe3O4 nanorods assembled into a mesoporous hybrid composite used as a high-performance lithium-ion battery anode material
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DOI：
10.1039/c6qm00252h
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发表时间：
2017-06-01
影响因子：
7
通讯作者：
Chi, Qijin
中科院分区：
文献类型：
--
作者：
Huang, Wei;Xiao, Xinxin;Chi, Qijin
新型负极材料的发现及其精细结构的设计是新一代锂离子电池（LIB）开发的核心要素。为此，我们在此报告了一种新型纳米结构复合材料，由约 75% Fe3O4 纳米棒和 25% 还原氧化石墨烯 (rGO) 组成。显微镜和光谱分析表明，Fe3O4 纳米棒通过共价键被 rGO 纳米片包裹（或封装），进一步自组装成由石墨烯基质网络化的介孔杂化复合材料。该复合材料平均孔径约为20 nm，比表面积高达152 m(2) g(-1)，是传统Fe3O4粉末的76倍。我们使用该复合材料作为锂离子电池负极材料来制造以锂为正极的硬币型原型电池。系统的半电池测试评估表明，本复合材料的电化学性能是过渡金属氧化物基锂离子电池负极材料中最好的。其性能特点是在500 mA g(-1)下进行250次充放电循环后具有1053 mA h g(-1)的高可逆容量，以及在应用1000-5000 mA g(-1)高电流密度时可提供788-541 mA h g(-1)能量的优异倍率性能。总的来说，我们已经证明 Fe3O4 纳米棒-rGO 杂化复合材料是一种有趣且有前途的用于制造 LIB 阳极的材料。
The discovery of new anode materials and engineering their fine structures are the core elements in the development of new-generation lithium ion batteries (LIBs). To this end, we herein report a novel nanostructured composite consisting of approximately 75% Fe3O4 nanorods and 25% reduced graphene oxide (rGO). Microscopy and spectroscopy analyses have identified that the Fe3O4 nanorods are wrapped (or encapsulated) by the rGO nanosheets via covalent bonding, which further self-assemble into a mesoporous hybrid composite networked by the graphene matrix. The composite has an average pore size around 20 nm and exhibits a high surface area of 152 m(2) g(-1), which is 76 times as high as that of conventional Fe3O4 powder. We have used the composite as an LIB anode material to fabricate coin-type prototype cells with lithium as the cathode. Systematic half-cell testing evaluations show that the electrochemical performance of the present composite material is amongst the best of the transition metal-oxide based LIB anode materials. The performances are characterized by a high reversible capacity of 1053 mA h g(-1) subjected to 250 charge-discharge cycles at 500 mA g(-1) and an excellent rate capability with the deliverable energy of 788-541 mA h g(-1) upon the application of high current densities of 1000-5000 mA g(-1). Overall, we have demonstrated that Fe3O4 nanorod-rGO hybrid composite is an interesting and promising material for the fabrication of LIB anodes.