Mg2Si promoted magnesio-mechanical reduction of silica into silicon nanoparticles for high-performance Li-ion batteries
Mg2Si promoted magnesio-mechanical reduction of silica into silicon nanoparticles for high-performance Li-ion batteries
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DOI：
10.1016/j.jssc.2021.122408
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发表时间：
2021-07-15
影响因子：
3.3
通讯作者：
Li, Xingguo
中科院分区：
文献类型：
--
作者：
Chen, Shunpeng;Wu, Xiao;Li, Xingguo
在这项研究中，我们报道了一种可伸缩的磁力还原方法，以低成本的原料制备出具有良好储锂性能的高质量纳米硅。虽然镁和二氧化硅的反应在热力学上是非常有利的，但使用商品化的镁粉在室温下通过机械球磨进行直接反应是困难的。而添加5wt%的Mg2Si后，以市售镁为还原剂，机械球磨250rpm，5h即可将二氧化硅纳米颗粒还原为硅纳米颗粒。机理研究表明，镁硅具有较高的刚性模数，能有效地破坏镁的表面氧化层，并生成新的镁表面以引发反应。所制得的纳米硅和Si@C复合材料表现出了与最先进的纳米硅负极材料相当的优异的储锂性能。
In this study, we report a scalable magnesio-mechanical reduction method to prepare high quality silicon nanoparticles with good lithium storage performance using low cost starting materials. Although the reaction of Mg and silica is thermodynamically highly favorable, direct reaction using commercial Mg powder by mechanical milling at room temperature is difficult. However, by adding of 5 wt % Mg2Si, silica nanoparticles can be reduced into Si nanoparticles using commercial Mg as the reductant by mechanical milling at 250 rpm in 5 h. Mechanism study suggests that Mg2Si can effectively break the surface oxide layer of Mg due to its high rigidity modules and create fresh Mg surface to initiate the reaction. The obtained Si nanoparticles and Si@C composites exhibit excellent lithium storage performance comparable to that of the state-of-the-art nano-Si anode materials.