Lithium Ion Battery Peformance of Silicon Nanowires with Carbon Skin
Lithium Ion Battery Peformance of Silicon Nanowires with Carbon Skin
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DOI：
10.1021/nn405710w
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发表时间：
2014-01-01
期刊：
影响因子：
17.1
通讯作者：
Korgel, Brian A.
中科院分区：
文献类型：
--
作者：
Bogart, Timothy D.;Oka, Daichi;Korgel, Brian A.
硅（Si）纳米材料已成为下一代锂离子电池阳极的主要候选材料。然而，硅的低导电性要求在阳极膜中使用导电添加剂。在这里，我们报告了一种基于溶液的硅纳米线的合成与导电碳皮肤。在不添加任何导电添加剂的情况下，硅纳米线电极在C/10下循环100次时的容量超过2000 mA h g(-1)，在1C下与锂金属快速循环时的容量超过1200 mA h g（-1）。原位透射电子显微镜（TEM）观察表明，碳皮具有双重作用：它显著加速了硅纳米线的锂化，同时也限制了最终的体积膨胀。目前的工作揭示了通过巧妙地定制硅和碳材料组成的纳米结构来优化锂电池性能的方法。
Silicon (Si) nanomaterials have emerged as a leading candidate for next generation lithium-ion battery anodes. However, the low electrical conductivity of Si requires the use of conductive additives in the anode film. Here we report a solution-based synthesis of Si nanowires with a conductive carbon skin. Without any conductive additive, the Si nanowire electrodes exhibited capacities of over 2000 mA h g(-1) for 100 cycles when cycled at C/10 and over 1200 mA h g(-1) when cycled more rapidly at 1C against Li metal. In situ transmission electron microscopy (TEM) observation reveals that the carbon skin performs dual roles: it speeds lithiation of the Si nanowires significantly, while also constraining the final volume expansion. The present work sheds light on ways to optimize lithium battery performance by smartly tailoring the nanostructure of composition of materials based on silicon and carbon.