Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, South Korea.
Nano Lett. 2013 Jul 10;13(7):3403-7. doi: 10.1021/nl401836c. Epub 2013 Jun 17.
A novel architecture consisting of Si nanowires internally grown from porous graphite is synthesized by etching of graphite with a lamellar structure via a VLS (vapor-liquid-solid) process. This strategy gives the high electrode density of 1.5 g/cm(3), which is comparable with practical anode of the Li-ion battery. Our product demonstrates a high volumetric capacity density of 1363 mAh/cm(3) with 91% Coulombic efficiency and high rate capability of 568 mAh/cm(3) even at a 5C rate. This good electrochemical performance allows porous graphite to offer free space to accommodate the volume change of Si nanowires during cycling and the electron transport to efficiently be improved between active materials.
通过 VLS（气-液-固）工艺对具有层状结构的石墨进行刻蚀，合成了一种由多孔石墨内部生长的 Si 纳米线组成的新型结构。该策略可实现 1.5 g/cm³的高电极密度，与锂离子电池的实际阳极相当。我们的产品展示了 1363 mAh/cm³的高体积容量密度，91%的库仑效率和 568 mAh/cm³的高倍率性能，即使在 5C 倍率下也是如此。这种良好的电化学性能使多孔石墨能够为 Si 纳米线在循环过程中的体积变化提供自由空间，并有效提高活性材料之间的电子传输。
