Hierarchical 3D mesoporous silicon@graphene nanoarchitectures for lithium ion batteries with superior performance
Hierarchical 3D mesoporous silicon@graphene nanoarchitectures for lithium ion batteries with superior performance
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DOI：
10.1007/s12274-013-0374-y
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发表时间：
2014-01-01
期刊：
影响因子：
9.9
通讯作者：
Wang, Guoxiu
中科院分区：
文献类型：
--
作者：
Chen, Shuangqiang;Bao, Peite;Wang, Guoxiu
硅被认为是最有前途的高容量锂离子电池负极材料。然而，在充电和放电期间的大的体积变化导致Si电极的粉化和循环时的快速容量损失。Si电极的这个缺点可以通过与组织良好的石墨烯泡沫组合来克服。本文采用热气泡喷射辅助化学气相沉积和镁热还原法成功制备了碳包覆介孔硅纳米球@石墨烯泡沫（C@Si@GF）纳米结构。采用场发射扫描电子显微镜、透射电子显微镜和拉曼光谱对复合材料的形貌和结构进行了表征。当用作锂离子电池的负极材料时，C@Si@GF纳米复合材料表现出上级的电化学性能，包括在1 A/g的电流密度下1，200 mAh/g的高比容量、优异的高倍率性能和优异的循环性能。事后分析表明，3D C@Si@GF电极在200次循环后的形态保持良好。介孔硅纳米球和石墨烯泡沫纳米结构的组合所产生的协同效应可以解决硅电极的棘手的粉化问题。
Silicon has been recognized as the most promising anode material for high capacity lithium ion batteries. However, large volume variations during charge and discharge result in pulverization of Si electrodes and fast capacity loss on cycling. This drawback of Si electrodes can be overcome by combination with well-organized graphene foam. In this work, hierarchical three-dimensional carbon-coated mesoporous Si nanospheres@graphene foam (C@Si@GF) nanoarchitectures were successfully synthesized by a thermal bubble ejection assisted chemical-vapor-deposition and magnesiothermic reduction method. The morphology and structure of the as-prepared nanocomposites were characterized by field emission scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. When employed as anode materials in lithium ion batteries, C@Si@GF nanocomposites exhibited superior electrochemical performance including a high specific capacity of 1,200 mAh/g at the current density of 1 A/g, excellent high rate capabilities and an outstanding cyclability. Post-mortem analyses identified that the morphology of 3D C@Si@GF electrodes after 200 cycles was well maintained. The synergistic effects arising from the combination of mesoporous Si nanospheres and graphene foam nanoarchitectures may address the intractable pulverization problem of Si electrode.