Won Chul Cho, Hye Jin Kim, Hae In Lee, Myung Won Seo, Ho Won Ra, Sang Jun Yoon, Tae Young Mun, Yong Ku Kim, Jae Ho Kim, Bo Hwa Kim, Jin Woo Kook, Chung-Yul Yoo, Jae Goo Lee, and Jang Wook Choi
Nano Lett., 2016, 16 (11), pp 7261–7269
Publication Date (Web): October 24, 2016
Copyright © 2016 American Chemical Society
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 (SiO2) has also been introduced as an alternative method. Here, we demonstrate the reduction of SiO2 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 SiO2 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–1 after 200 cycles.