One-pot synthesis of hematite@graphene core@shell nanostructures for superior lithium storage
One-pot synthesis of hematite@graphene core@shell nanostructures for superior lithium storage
复制标题
一锅法合成赤铁矿@石墨烯核@壳纳米结构以实现优异的锂存储
DOI：
10.1039/c3nr03484d
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发表时间：
2013-01-01
期刊：
影响因子：
6.7
通讯作者：
Guo, Lin
中科院分区：
文献类型：
--
作者：
Chen, Dezhi;Quan, Hongying;Guo, Lin
在温和的湿化学条件下，采用表面活性剂控制的一锅法成功合成了新型的赤铁矿@石墨烯复合材料。X射线衍射（XRD）、拉曼光谱、扫描电子显微镜（SEM）和透射电子显微镜（TEM）等表征结果表明，纳米赤铁矿颗粒被石墨烯层包裹，形成了核壳结构。采用恒流充放电和交流阻抗技术研究了赤铁矿@石墨烯核壳纳米结构作为锂离子电池负极的电化学性能。所制备的赤铁矿@石墨烯核-壳纳米结构在200 mA g（-1）（0.2 C）的电流密度下在180次循环后表现出1040 mA h g（-1）的高可逆比容量以及优异的倍率性能和长循环寿命。在6C的高倍率下，经过200次循环后，其可逆容量仍高达500 mA·h·g ~（-1）。电化学测试结果表明，一锅法制备的赤铁矿@石墨烯复合材料是一种很有前途的锂离子电池负极材料。
Novel hematite@graphene composites have been successfully synthesized by a one-pot surfactant governed approach under mild wet-chemical conditions. A series of characterizations including X-ray diffraction (XRD), Raman spectrum, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the hematite nanoparticles with relatively uniform size were encapsulated by graphene layers and were able to form core-shell nanostructures. The electrochemical properties of hematite@graphene core-shell nanostructures as anodes for lithium-ion batteries were evaluated by galvanostatic charge-discharge and AC impedance spectroscopy techniques. The as-prepared hematite@graphene core-shell nanostructures exhibited a high reversible specific capacity of 1040 mA h g(-1) at a current density of 200 mA g(-1) (0.2 C) after 180 cycles and excellent rate capability and long cycle life. Furthermore, a reversible capacity as high as 500 mA h g(-1) was still achieved after 200 cycles even at a high rate of 6 C. The electrochemical test results show that the hematite@graphene composites prepared by the one-pot wet chemical method are promising anode materials for lithium-ion batteries.