An Yongling, Fei Huifang, Zeng Guifang, Ci Lijie, Xiong Shenglin, Feng Jinkui, Qian Yitai
SDU & Rice Joint Center for Carbon Nanomaterials, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), School of Materials Science and Engineering , Shandong University , Jinan 250061 , China.
School of Chemistry and Chemical Engineering , Shandong University , Jinan 250100 , China.
ACS Nano. 2018 May 22;12(5):4993-5002. doi: 10.1021/acsnano.8b02219. Epub 2018 Apr 25.
Silicon is considered as one of the most favorable anode materials for next-generation lithium-ion batteries. Nanoporous silicon is synthesized via a green, facile, and controllable vacuum distillation method from the commercial MgSi alloy. Nanoporous silicon is formed by the evaporation of low boiling point Mg. In this method, the magnesium metal from the MgSi alloy can be recycled. The pore sizes of nanoporous silicon can be secured by adjusting the distillated temperature and time. The optimized nanoporous silicon (800 °C, 0.5 h) delivers a discharge capacity of 2034 mA h g at 200 mA g for 100 cycles, a cycling stability with more than 1180 mA h g even after 400 cycles at 1000 mA g, and a rate capability of 855 mA h g at 5000 mA g. The electrochemical properties might be ascribed to its porous structure, which may accommodate large volume change during the cycling process. These results suggest that the green, scalable, and controllable approach may offer a pathway for the commercialization of high-performance Si anodes. This method may also be extended to construct other nanoporous materials.
硅被认为是下一代锂离子电池最理想的负极材料之一。通过一种绿色、简便且可控的真空蒸馏方法，由商用MgSi合金合成了纳米多孔硅。纳米多孔硅是通过低沸点Mg的蒸发形成的。在该方法中，MgSi合金中的镁金属可以回收利用。通过调节蒸馏温度和时间可以确保纳米多孔硅的孔径。优化后的纳米多孔硅（800℃，0.5小时）在200 mA g下循环100次时的放电容量为2034 mA h g，在1000 mA g下循环400次后仍具有超过1180 mA h g的循环稳定性，在5000 mA g下的倍率性能为855 mA h g。其电化学性能可能归因于其多孔结构，该结构可以在循环过程中容纳较大的体积变化。这些结果表明，这种绿色、可扩展且可控的方法可能为高性能硅负极的商业化提供一条途径。该方法也可扩展用于构建其他纳米多孔材料。
