Korea Institute of Energy Research (KIER) , 152 Gajeong-ro, Yuesong-gu, Daejeon 34129, Republic of Korea.
Department of Advanced Energy and Technology, Korea University of Science and Technology , 217 Gajeong-ro, Yuesong-gu, Daejeon 34113, Republic of Korea.
Nano Lett. 2016 Nov 9;16(11):7261-7269. doi: 10.1021/acs.nanolett.6b03762. Epub 2016 Oct 31.
Nanostructured silicon (Si) is useful in many applications and has typically been synthesized by bottom-up colloid-based solution processes or top-down gas phase reactions at high temperatures. These methods, however, suffer from toxic precursors, low yields, and impractical processing conditions (i.e., high pressure). The magnesiothermic reduction of silicon oxide (SiO) has also been introduced as an alternative method. Here, we demonstrate the reduction of SiO by a simple milling process using a lab-scale planetary-ball mill and industry-scale attrition-mill. Moreover, an ignition point where the reduction begins was consistently observed for the milling processes, which could be used to accurately monitor and control the reaction. The complete conversion of rice husk SiO to high purity Si was demonstrated, taking advantage of the rice husk's uniform nanoporosity and global availability, using a 5L-scale attrition-mill. The resulting porous Si showed excellent performance as a Li-ion battery anode, retaining 82.8% of the initial capacity of 1466 mAh g after 200 cycles.
纳米结构硅（Si）在许多应用中很有用，通常通过基于胶体的自上而下的溶液工艺或高温下的自上而下的气相反应合成。然而，这些方法存在毒性前体、低产率和不切实际的加工条件（即高压）的问题。硅氧化物（SiO）的镁热还原也被引入作为一种替代方法。在这里，我们展示了使用实验室规模行星球磨机和工业规模磨损机通过简单的研磨工艺还原 SiO。此外，在研磨过程中观察到还原开始的点火点，可以用于准确监测和控制反应。利用稻壳的均匀纳米多孔性和全球可用性，在 5L 规模的磨损机中，成功地将稻壳 SiO 完全转化为高纯度 Si。所得多孔硅作为锂离子电池阳极表现出优异的性能，在 200 次循环后保留了初始容量 1466 mAh g 的 82.8%。
