碳塗佈於矽複合材料的製備與其應用於鋰離子電池負極之研究

The Study of Preparation for Carbon-coated Silicon Composites as Anode Materials of Li-ion Batteries

曾學毅(Hsueh-Yi Tseng)

指導教授 ： 顏溪成

國立臺灣大學/工學院/化學工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10420

摘要

本論文主要目的是研究以矽為主體的鋰離子二次電池負極材料。矽的高電容量(~4200mAh/g)是取代目前常用的石墨(372 mAh/g)負極材料的一大優勢。但矽在充放電的過程中會伴隨著劇烈的體積變化(400%)與本身的低導電度，使得其在鋰離子電池中的應用性受到了侷限。為了解決上述所存在的問題，在本研究中試圖解決其體積變化的問題，將碳披覆在矽表面上，以及找出組電池的最適當比例及製作條件。
首先本實驗以檸檬酸為前驅物，在氮氣氣氛下經由熱處理將其裂解成不定型碳，而附著在矽表面上及電極上。在矽的使用上，進行前處理和縮小粒徑可有效改善循環次數。而在組裝成電池時，導電添加劑可有效增加電池表現，幫助鋰離子擴散到矽上且遷入形成合金。以本實驗的製程，取檸檬酸和奈米級矽重量比5：1的條件下，以無水酒精作為溶劑分散後，在600oC下在管狀高溫爐，以氮氣氣氛下進行6小時的燒結，做出碳矽複合材料後塗在銅箔上，再以活性材料：導電添加劑：黏著劑=45：45：10(或60：30：10)的條件下，製備鋰離子電池的負極可得到較佳的電池性能表現。

關鍵字

鋰離子電池 ； 矽 ； 負極材料 ； 碳矽複合材料

並列摘要

The main purpose of this research is to explore new negative electrode materials based on silicon for lithium-ion battery. The high theoretical capacity of silicon (~4200 mAh/g) is superior to that of graphite (372 mAh/g) as anode materials. However, Si has the disadvantage of dramatic volumetric variation during cycling and its low conductivity. Carbon-coated Si composite materials are prepared in this study to overcome the problems just mentioned. In this study the negative electrode materials prepared from various conditions was investigated by discharge/charge cycles of the coin cells containing Si electrodes and Li foil.
Carbon-coated Si materials have been prepared by the thermal treatment of solution of Si particles and citric acid dissolved in the 99.5% alcohol into the quartz tube in nitrogen atmosphere. The thermal treatment of calcination at high temperature was to form the amorphous carbon layer onto the surface of Si particles. The experimental results show that the nano-scale silicon particles has better cycle performance after dilute HF pretreatment. Also the calcination process at 600oC for 6 hours would significantly improve cycle performance. Besides, the addition of KS-6(conductive additives)in the coin cell tests would also enhance the capacity and cycle performance.

並列關鍵字

Lithium-ion battery ； Silicon ； Negative electrode ； C/Si composite

參考文獻

4. 林群耀, 鋰電池巨觀與微觀雙尺度數學模擬, in 臺灣大學化學工程學研究所學位論文2010, 臺灣大學. p. 1-142.

41. 劉偉仁, 鋰離子電池矽負極材料之製備與特性分析, in 臺灣大學化學工程學研究所學位論文2006, 臺灣大學. p. 1-209.

2. Armand, M. and P. Touzain, Graphite Intercalation Compounds as Cathode Materials. Materials Science and Engineering, 1977. 31: p. 319-329.

5. Abraham, K.M., D.M. Pasquariello, and D.A. Schwartz, Practical Rechargeable Lithium Batteries. Journal of Power Sources, 1989. 26(1-2): p. 247-255.

6. Brandt, K. and F.C. Laman, Reproducibility and Reliability of Rechargeable Lithium Molybdenum-Disulfide Batteries. Journal of Power Sources, 1989. 25(4): p. 265-276.