Tin dioxide@carbon core-shell nanoarchitectures anchored on wrinkled graphene for ultrafast and stable lithium storage.
Tin dioxide@carbon core-shell nanoarchitectures anchored on wrinkled graphene for ultrafast and stable lithium storage.
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DOI：
10.1021/am5007194
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发表时间：
2014-05
影响因子：
9.5
通讯作者：
Xunfu Zhou;Weijian Liu;Xiaoyuan Yu;Yingju Liu;Yueping Fang;S. Klankowski;Yiqun Yang;J. E. Brown;Jun Li
中科院分区：
文献类型：
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作者：
Xunfu Zhou;Weijian Liu;Xiaoyuan Yu;Yingju Liu;Yueping Fang;S. Klankowski;Yiqun Yang;J. E. Brown;Jun Li
通过简单的水热烧结工艺成功合成了SnO2@C@GS复合材料作为一种新型的三维纳米结构。这种三维纳米结构由SnO2@C核壳纳米球和纳米链组成，纳米链固定在皱褶的石墨烯片（GSs）上。透射电镜显示，这些核壳纳米粒子由直径3 ~ 9 nm的二次氧化锡纳米粒子包裹在直径约50 nm的原生碳纳米球中组成。大量的核壳纳米粒子均匀地附着在皱巴巴的石墨烯纳米片表面，其中一部分进一步连接成纳米链。这种新的3D纳米结构由两种不同的碳缓冲基质组成，即葡萄糖碳化产生的碳层和添加的GS模板，从而增强了锂的存储性能。通过恒流充放电循环和电化学阻抗谱对SnO2@C@GS复合材料的锂循环性能进行了评价。结果表明，当电流密度为200 mA g（-1）时，SnO2@C@GS复合材料在第20次、第50次和第100次循环时的放电容量分别为883.5、845.7和8305 mA h g(-1)；当放电速率为1680 mA g（-1）时，放电容量为645.2 mA h g（-1）。这种新的3D纳米结构具有高容量和优异的循环和倍率性能，作为锂存储的高倍率和稳定的阳极材料具有很大的潜力。
The SnO2@C@GS composites as a new type of 3D nanoarchitecture have been successfully synthesized by a facile hydrothermal process followed by a sintering strategy. Such a 3D nanoarchitecture is made up of SnO2@C core-shell nanospheres and nanochains anchored on wrinkled graphene sheets (GSs). Transmission electron microscopy shows that these core-shell nanoparticles consist of 3-9 nm diameter secondary SnO2 nanoparticles embedded in about 50 nm diameter primary carbon nanospheres. Large quantities of core-shell nanoparticles are uniformly attached to the surface of wrinkled graphene nanosheets, with a portion of them further connected into nanochains. This new 3D nanoarchitecture consists of two different kinds of carbon-buffering matrixes, i.e., the carbon layer produced by glucose carbonization and the added GS template, leading to enhanced lithium storage properties. The lithium-cycling properties of the SnO2@C@GS composite have been evaluated by galvanostatic discharge-charge cycling and electrochemical impedance spectroscopy. Results show that the SnO2@C@GS composite has discharge capacities of 883.5, 845.7, and 830.5 mA h g(-1) in the 20th, 50th and 100th cycles, respectively, at a current density of 200 mA g(-1) and delivers a desirable discharge capacity of 645.2 mA h g(-1) at a rate of 1680 mA g(-1). This new 3D nanoarchitecture exhibits a high capability and excellent cycling and rate performance, holding great potential as a high-rate and stable anode material for lithium storage.