https://scholars.lib.ntu.edu.tw/handle/123456789/74442
標題: | 新製程DPG石墨吸附電解質分解之氣體及其提昇鋰離子二次電池性能之研究(I) | 作者: | 李源弘 | 關鍵字: | 人工石墨;fullerenes;Carbon Nanotube;理論容量密度;artificial graphite | 公開日期: | 2002 | 出版社: | 臺北市:國立臺灣大學材料科學與工程學研究所 | 摘要: | 隨著可攜式電子產品日益受重視,其相關組件的性能也需隨之增強。故儲能材料也順應時代的趨勢,走向輕、薄、短、小的境界,其中鋰離子二次電池具能量密度高、循環壽命長、重量輕等優點而受青睞,也因此不可不注意它的安全性。鋰離子二次電池中的電解液常會因電池過度充電與過度放電而導致電解液分解產生氣體,而根據研究,當電池過充與過放時,所產生氣體的量較無過充過放時氣體的量多了5-20 倍,尤其是在過放的情形下。此時產生的大量氣體會使電池產生過大的內壓,並造成短路,同時電池內的阻抗也大幅提昇,此時電池正處於危險的狀態下, 必須適時地處理這些氣體,以避免發生危險。由本實驗室所研發之人工石墨含有自然衍生性的C60 與Carbon Nanotube,此兩 種特殊結構物均會吸附電解液所產生的大量氣體,降低內壓以避免發生危險。另一方面,此人工石墨也因含有C60 和Carbon Nanotube,其能量密度高於一般人工石墨,甚至已超過完美石墨的理論能量密度372mAh/g。故本實驗室所自製之人工石墨 不僅擁有高能量密度;而在電池安全性方面,當電池過充與過放時,此人工石墨會吸附氣體,也因此提高了鋰離子二次電池 的安全性。 Electronic products are more important day by day; the performances of their relative components are needed to be much better. And electrochemical storage devices also can keep up with world’s trend, which are towards “light”, “thin”, “short”, and “small”. Li-ion rechargeable battery owns many advantages of high energy density, long cycles, and light weight, and consequently its security is very important. Under overcharge and overdischarge, electrolyte of Li-ion rechargeable battery is often decomposed to produce many kinds of gases. According to the reports, Li-ion rechargeable battery being on its performance, the amount of gases found to be 5 to 20 times more than after charge and discharge. Especially during its overdischarge, a great deal of gases result in high pressure and circuit. In the meantime, the resistance of Li-ion rechargeable battery increases apparently and put the battery into the dangerous situation. In order to avoid these dangers, it is necessary for these gases with dealing properly somehow. The artificial graphite manufactured in our laboratory has been investigated. It possesses natural derivative fullerenes ( C60 ) and Carbon Nanotube ( CNT ). And both of these two special structures could absorb a great deal of gases from decomposing electrolyte to decrease pressure. Besides, the energy density of the artificial graphite with C60 and CNT is higher than conventional artificial graphite even over theoretical 3 energy density 372mAh/g. Therefore, the artificial graphite from our laboratory and has been investigated, owns not only high energy density but also excellent security. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/12401 | 其他識別: | 902212E002235 | Rights: | 國立臺灣大學材料科學與工程學研究所 |
顯示於: | 材料科學與工程學系 |
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902212E002235.pdf | 241.05 kB | Adobe PDF | 檢視/開啟 |
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