- 學位論文
利用多元醇還原法合成二氧化錳奈米線於超級電容器上之應用
Synthesis of manganese dioxide nanowires by polyol process and its application for supercapacitor
摘要
本論文主要以合成二氧化錳奈米線氧化物結構為活性材料並應用於儲能裝置-超級電容器上，合成方式以多元醇還原法並且於不同反應時間迴流下得到束狀二氧化錳奈米線，結果顯示以6小時製備可得線狀比例較佳之一維結構二氧化錳奈米線，直徑為3–20 nm，此材料再通入氮氣於250 oC、定溫1小時進行下鍛燒可得結晶結構較佳的二氧化錳奈米線。我們以掃描式電子顯微鏡觀察合成之二氧化錳奈米線形態和結構，再以熱重損失分析儀(TGA)、穿透式電子顯微鏡(TEM)、X光繞射儀(XRD)、X射線電子能譜儀(XPS)和拉曼光譜儀(Raman)進行材料特性分析。 在超級電容器的研究方面，以石墨電極為電極，將合成之二氧化錳奈米線與鍛燒後的二氧化錳奈米線塗佈於石墨電極上並作電化學測試，測試循環伏安、充放電測試，於掃描速率2 mV/s下，二氧化錳奈米線之電容值為136.11 F/g；而鍛燒後的二氧化錳奈米線之電容值為304.66 F/g，於掃描速率100 mV/s下，長時間循環伏安5000圈測試後，電容值仍有70 %之保留率。
並列摘要
This research aims to synthesize the manganese dioxide (MnO2) nanowires, which has been widely used as the energy storge materials, as the supercapacitor. Polyol process was conducted to the synthesis of the MnO2 nanowires with the KMnO4, PEG200 and carbon nanomaterials at 100 oC for a period of time. The result shows that MnO2 nanowires with a mean diameter of 7–20 nm can be obtained. Characterization of the materials was carried out by SEM, TGA, TEM, XRD, XPS and Raman. The electrochemical performance of the MnO2 nanowires was investigated by cyclic voltammetry(CV), galvanostatic charge-discharge (GCD) and EIS. The results show that a maximum capacitance of 304.66 F/g can be achieved with a scan rate 2 mV/s and retention is about 70 % after 5000 cycles.