從切割矽製備多孔/奈米矽及其鋰電池應用之研究

Preparation of Porous/Nano Silicon from Kerf Loss Waste for Lithium-ion Batteries Application

楊乃維(NAI-WEI YANG)

指導教授 ： 藍崇文

國立臺灣大學/工學院/化學工程學研究所/碩士(1995年)

https://doi.org/10.6342/NTU202104323

摘要

為了發展便宜的矽負極材料和解決其在鋰電池充放電過程中體積膨脹 300%的問題，吾人決定以低成本的切割矽做為原料，先反應成中間產物矽化鎂，再除鎂形成多孔矽，最後再利用金屬催化蝕刻多孔矽以製備成奈米矽。
矽化鎂方面，吾人成功以氣相鎂化方式，在高壓釜中將切割矽反應成粒徑大小相同的 1 微米矽化鎂。多孔矽部分則是利用小粒徑的矽化鎂和 CO2/N2混氣經過氣相反應，接著透過酸洗除去副產物形成孔洞，成功得到比表面積高達 500 m2 g-1的多孔矽。奈米矽則是利用銅金屬催化蝕刻，蝕刻多孔矽，最佳條件能得到平均粒徑 50nm 的奈米矽。
此製程的優勢在於，一為切割矽是低成本高品質的原料來源，二為吾人將切割矽製備成多孔矽後，較易於加工成更小粒徑的奈米矽，可以省去大量的成本和時間， 有助於推廣鋰電池矽負極材料的發展。

關鍵字

切割矽 ； 矽化鎂 ； 多孔矽 ； 金屬催化蝕刻 ； 奈米矽

並列摘要

In order to develop the low-cost silicon anode material and resolve the problem of 300% volume expansion during the charge and discharge process, we decide to choose the kerf-loss silicon as the raw material. First, we will make it into the intermediate product Mg2Si, and then remove the magnesium to generate the porous silicon. Finally, we will use the metal assisted chemical etching(MACE) to etch the porous silicon to become the nano silicon particle.
For Mg2Si, we utilize the gas phase magnesiothermic reaction and self-design autoclave to get the 1μm scale Mg2Si as the kerf-loss waste. And we succeed in getting porous silicon with high BET specific surface area up to 500 m2g-1, through the reaction by Mg2Si and mixture gas CO2/N2 following by the acid pickling. At last, we can get the average size around 50nm nano silicon particle if we use the best condition of MACE to etch the porous silicon.
The advantage of this procedure first depends on the kerf-loss silicon, which is the lowcost and high-quality raw material. Second, porous silicon is easier to be made into the nano silicon, which can save the cost and time of processing. This can promote the development of silicon anode material of LIBs.

並列關鍵字

kerf loss silicon ； magnesium silicide ； porous silicon ； metal assisted chemical etching ； nano silicon

參考文獻

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